Autoimmune uveitis is a sight-threatening disease mainly caused by dysregulation of immunity. We investigated the therapeutic effects of green tea extract (GTE) and its major component, epigallocatechin-3-gallate (EGCG), on a murine model of experimental autoimmune uveoretinitis (EAU). Oral administration of GTE, EGCG, dexamethasone, or water, which started 5 days before the induction, was fed every two days to each group. On day 21 post induction, the eyes were examined by confocal scanning laser ophthalmoscopy, optical coherence tomography (OCT), fundus fluorescein angiography (FFA) and electroretinography (ERG) prior to sacrificing the animals for histological assessments and gene expression studies. Retinal-choroidal thicknesses (RCT) and major retinal vessel diameter were measured on OCT sections and FFA images, respectively. Comparing to water-treated EAU animals, GTE attenuated uveitis clinical manifestations, RCT increase (1.100 ± 0.013 times vs 1.005 ± 0.012 times, P < 0.001), retinal vessel dilation (308.9 ± 6.189 units vs 240.8 units, P < 0.001), ERG amplitudes attenuation, histopathological ocular damages, and splenomegaly in EAU mice. The therapeutic effects of GTE were dose dependent and were comparable to dexamethasone. EGCG, a major active constituent of GTE, partially alleviated uveitic phenotypes including recovering visual function. Th-17 associated pro-inflammatory gene [interleukin 1 beta (IL-1β), IL-6, IL-17A, and tumor necrosis factor alpha (TNF-α)] expressions were down regulated by GTE and EGCG treatments, which showed no detectable morphological defects in liver and kidney in non-induced and EAU mice. Our findings suggest that GTE consumption can serve as a potent therapeutic agent as well as a food supplement for developing alternative treatments against autoimmune uveitis.

Inflammation is in a wide spectrum of retinal diseases, causing irreversible blindness and visual impairment. We have previously demonstrated that Green Tea Extract (GTE) is a potent anti-inflammatory agent for anterior uveitis. Here we investigated the anti-inflammatory effect of GTE on lipopolysaccharides (LPS)-induced retinal inflammation in rats and explored the underlying mechanism. Adult rats were injected with LPS and GTE was administered intra-gastrically at 2, 8, 26 and 32 hours post-injection. Staining of whole-mount retina showed that the number of activated microglia cells was significantly increased at 48 hours post-injection, which was suppressed after GTE treatment in a dose-dependent manner. Activation of astrocytes and Müller glia in the retina was also suppressed after GTE treatment. Meanwhile, GTE reduced the expression of pro-inflammatory cytokines including IL-1β, TNF-α and IL-6 in retina and vitreous humor. These anti-inflammatory effects were associated with a reduced phosphorylation of STAT3 and NF-κB in the retina. Furthermore, the surface receptor of EGCG, 67LR, was localized on the neurons and glia in the retina. These findings demonstrate that GTE is an effective agent in suppressing LPS-induced retinal inflammation, probably through its potent anti-oxidative property and a receptor-mediated action on transcription factors that regulate production of pro-inflammatory cytokines.

Green tea extracts exhibit anti-oxidative and anti-inflammatory actions in different disease conditions. We hypothesized that green tea extract and its catechin constituents ameliorate sodium iodate-induced retinal degeneration in rats by counteracting oxidative stress. In this study, adult Sprague-Dawley rats were intravenously injected with a single dose of sodium iodate. Green tea extract (GTE; Theaphenon-E) or combinations of its catechin constituents, including (-)-epigallocatechin gallate (EGCG), were administered intra-gastrically before injection. Live imaging analysis using confocal scanning laser ophthalmoscopy and spectral-domain optical coherence tomography showed a progressive increase of degenerating profile across the retinal surface and decrease in thickness of outer nuclear layer (ONL) at Day-14 of post-injection. These lesions were significantly ameliorated by Theaphenon-E and catechin combinations with EGCG. Catechins with exclusion of EGCG did not show obvious protective effect. Histological analyses confirmed that Theaphenon-E and catechins containing EGCG protect the retina by reducing ONL disruption. Retinal protective effects were associated with reduced expression of superoxide dismutase, glutathione peroxidase and caspase-3, and suppression of 8-iso-Prostaglandin F2α generation in the retina. In summary, GTE and its catechin constituents are potent anti-oxidants that offer neuroprotection to the outer retinal degeneration after sodium iodate insult, among which EGCG is the most active constituent.

Besides its metabolic and endocrine effects, growth hormone (GH)-releasing hormone (GHRH) is involved in the modulation of inflammation. Recently synthetized GHRH antagonist MIA-690 and MR-409, GHRH agonist, developed by us have shown potent pharmacological effects in various experimental paradigms. However, whether their administration modify resistance to chronic inflammatory stimuli in colon is still unknown. Ex vivo results demonstrated that MIA-690 and MR-409 inhibited production of pro-inflammatory and oxidative markers induced by lipopolysaccharide on isolated mouse colon specimens. In vivo, both MIA-690 and MR-409 have also been able to decrease the responsiveness to nociceptive stimulus, in hot plate test. Additionally, both peptides also induced a decreased sensitivity to acute and persistent inflammatory stimuli in male mice, in formalin test and dextran sodium sulfate (DSS)-induced colitis model, respectively. MIA-690 and MR-409 attenuate DSS-induced colitis with particular regard to clinical manifestations, histopathological damage and release of pro-inflammatory and oxidative markers in colon specimens. Respect to MR-409, MIA-690 showed higher efficacy in inhibiting prostaglandin (PG)E2, 8-iso-PGF2α and serotonin (5-HT) levels, as well as tumor necrosis factor (TNF)-α, interleukin (IL)-6 and nitric oxide synthase gene expression in colon specimens of DSS-induced colitis. Furthermore, MIA-690 decreased serum insulin-like growth factor (IGF)-1 levels in mice DSS-treated, respect to MR-409. Thus, our findings highlight the protective effects of MIA-690 and MR-409 on inflammation stimuli. The higher antinflammatory and antioxidant activities observed with MIA-690 could be related to decreased serum IGF-1 levels.

Association of a polymorphism rs3775291 in the toll-like receptor 3 (TLR3) gene with age-related macular degeneration (AMD) had been investigated intensively, with variable results across studies. Here we conducted a meta-analysis to verify the effect of rs3775291 on AMD. We searched for genetic association studies published in PubMed, EMBASE and Web of Science from start dates to March 10, 2015. Totally 235 reports were retrieved and 9 studies were included for meta-analysis, involving 7400 cases and 13579 controls. Summary odds ratios (ORs) with 95% confidence intervals (CIs) for alleles and genotypes were estimated. TLR3 rs3775291 was associated with both geographic atrophy (GA) and neovascular AMD (nAMD), with marginally significant pooled-P values. Stratification analysis by ethnicity indicated that rs3775291 was associated with all forms of AMD, GA and nAMD only in Caucasians (OR = 0.87, 0.78 and 0.77, respectively, for the TT genotype) but not in East Asians. However, the associations could not withstand Bonferroni correction. This meta-analysis has thus revealed suggestive evidence for TLR3 rs3775291 as an associated marker for AMD in Caucasians but not in Asians. This SNP may have only a small effect on AMD susceptibility. Further studies in larger samples are warranted to confirm its role.

Growth hormone-releasing hormone (GHRH) antagonist MIA-690 and GHRH agonist MR-409, previously synthesized and developed by us have demonstrated potent antitumor effects. However, little is known about the effects of these analogs on brain functions. We investigated the potential antinflammatory and antioxidant effects of GHRH antagonist MIA-690 and GHRH agonist MR-409, on isolated mouse prefrontal cortex specimens treated with lipopolysaccharide (LPS). Additionally, we studied their effects on emotional behavior after chronic in vivo treatment. Ex vivo, MIA-690 and MR-409 inhibited LPS-induced inflammatory and pro-oxidative markers. In vivo, both MIA-690 and MR-409 induced anxiolytic and antidepressant-like effects, increased norepinephrine and serotonin levels and decreased nuclear factor-kB, tumor necrosis factor-α and interleukin-6 gene expression in prefrontal cortex. Increased nuclear factor erythroid 2-related factor 2 expression was also found in mice treated with MIA-690 and MR-409. MIA-690 showed higher efficacy in inhibiting all tested inflammatory and oxidative markers. In addition, MR-409 induced a down regulation of the gene and protein expression of pituitary-type GHRH-receptor in prefrontal cortex of mice after 4 weeks of treatment at 5 µg/day. In conclusion, our results demonstrate anxiolytic and antidepressant-like effects of GHRH analogs that could involve modulatory effects on monoaminergic signaling, inflammatory and oxidative status.

Lung inflammation due to sarcoidosis is characterized by a complex cascade of immunopathologic events, including leukocyte recruitment and granuloma formation. α-melanocyte stimulating hormone (α-MSH) is a melanocortin signaling peptide with anti-inflammatory properties. We aimed to evaluate the effects of α-MSH in a novel in vitro sarcoidosis model. An in vitro sarcoidosis-like granuloma model was developed by challenging peripheral blood mononuclear cells (PBMCs) derived from patients with confirmed treatment-naïve sarcoidosis with microparticles generated from Mycobacterium abscessus cell walls. Unchallenged PBMCsand developed granulomas were treated daily with 10 μM α-MSH or saline as control. Cytokine concentrations in supernatants of culture and in cell extracts were measured using Illumina multiplex Elisa and western blot, respectively. Gene expression was analyzed using RNA-Seq and RT-PCR. Protein secretion and gene expression of IL-7, IL-7R, IFN-γ, MC1R, NF-κB, phosphorylated NF-κB (p-NF-κB), MARCO, and p-CREB were measured with western blot and RNAseq. A significant increase in IL-7, IL-7R, and IFN-γ protein expression was found in developed granulomas comparing to microparticle unchallenged PBMCs. IL-7, IL-7R, and IFN-γ protein expression was significantly reduced in developed granulomas after exposure to α-MSH compared with saline treated granulomas. Compared with microparticle unchallenged PBMCs, total NF-κB and p-NF-κB were significantly increased in developed granulomas, while expression of p-CREB was not changed. Treatment with α-MSH promoted a significantly higher concentration of p-CREB in granulomas. The anti-inflammatory effects of α-MSH were blocked by specific p-CREB inhibition. α-MSH has anti-inflammatory properties in this in vitro granuloma model, which is an effect mediated by induction of phosphorylation of CREB.

Genetic associations for keratoconus could be useful for understanding disease pathogenesis and discovering biomarkers for early detection of the disease. We conducted a systematic review and meta-analysis to summarize all reported genetic associations for the disease. We searched in the MEDLINE, Embase, Web of Science, and HuGENET databases for genetic studies of keratoconus published from 1950 to June 2016. The summary odds ratio and 95% confidence intervals of all polymorphisms were estimated using the random-effect model. Among 639 reports that were retrieved, 24 fulfilled required criteria as eligible studies for meta-analysis, involving a total of 53 polymorphisms in 28 genes/loci. Results of our meta-analysis lead to the prioritization of 8 single-nucleotide polymorphisms (SNPs) in 6 genes/loci for keratoconus in Whites. Of them 5 genes/loci were originally detected in genome-wide association studies, including FOXO1 (rs2721051, P = 5.6 × 10-11), RXRA-COL5A1 (rs1536482, P = 2.5 × 10-9), FNDC3B (rs4894535, P = 1.4 × 10-8), IMMP2L (rs757219, P = 6.1 × 10-7; rs214884, P = 2.3 × 10-5), and BANP-ZNF469 (rs9938149, P = 1.3 × 10-5). The gene COL4A4 (rs2229813, P = 1.3 × 10-12; rs2228557, P = 4.5 × 10-7) was identified in previous candidate gene studies. We also found SNPs in 10 genes/loci that had a summary P value < 0.05. Sensitivity analysis indicated that the results were robust. Replication studies and understanding the roles of these genes in keratoconus are warranted.