Comparison of uveitis induced by interleukin-8 (IL-8) and endotoxin in rabbits

IL-8 is a potent chemoattractant which has been postulated to play a role in the cytokine cascade associated with uveitis. The authors studied the effect of intravitreal IL-8 on the induction of uveitis in the rabbit. IL-8 at varying concentrations (1 ng, 10 ng or 100 ng) or endotoxin (100 ng) was injected intravitreally within the rabbit eye. At 6, 24 and 48 hours following injection the induction of uveitis was evaluated by clinical scoring, anterior chamber (AC) leukocyte count, AC protein concentration and histopathology in 15 rabbits. Only the 100 ng concentration of IL-8 induced uveitis at 6 and 24 hours by clinical scoring and AC leukocyte count; the AC protein concentration remained normal. In contrast, endotoxin caused a severe uveitis with a significant increase in all the parameters evaluated. The authors conclude that intravitreal IL-8, in the concentrations studied, induces a limited uveitis which is detectable at six hours and resolves within 48 hours. It is characterized by leukocyte infiltration without an increased AC protein concentration. Thus, IL-8 may play a role in the cytokine cascade involved in the induction of uveitis.     

Comparison of uveitis induced by interleukin-8 (IL-8) and endotoxin in rabbits

IL-8 is a potent chemoattractant which has been postulated to play a role in the cytokine cascade associated with uveitis. The authors studied the effect of intravitreal IL-8 on the induction of uveitis in the rabbit. IL-8 at varying concentrations (1 ng, 10 ng or 100 ng) or endotoxin (100 ng) was injected intravitreally within the rabbit eye. At 6, 24 and 48 hours following injection the induction of uveitis was evaluated by clinical scoring, anterior chamber (AC) leukocyte count, AC protein concentration and histopathology in 15 rabbits. Only the 100 ng concentration of IL-8 induced uveitis at 6 and 24 hours by clinical scoring and AC leukocyte count; the AC protein concentration remained normal. In contrast, endotoxin caused a severe uveitis with a significant increase in all the parameters evaluated. The authors conclude that intravitreal IL-8, in the concentrations studied, induces a limited uveitis which is detectable at six hours and resolves within 48 hours. It is characterized by leukocyte infiltration without an increased AC protein concentration. Thus, IL-8 may play a role in the cytokine cascade involved in the induction of uveitis     

CXC chemokine GRO is essential for neutrophil infiltration in LPS-induced uveitis in rabbits

The purpose of this study was to investigate the role and regulation of the CXC chemokine GRO and the interaction between GRO and IL-8 in LPS-induced uveitis in rabbits. Uveitis was induced by intravitreal injection of 100 ng of LPS in rabbits. After the LPS injection, GRO was produced in aqueous humor and peaked at 24 hr. Immunohistochemistry showed that ciliary epithelial cells were responsible for production of GRO. Blocking the activity of GRO by anti-GRO serum reduced LPS-induced aqueous neutrophil counts by 80%, but did not reduce the mononuclear cell counts or protein levels or IL-8 levels. Regulation of GRO production by TNFalpha, IL-1 and IL-8 was studied. Anti-TNFalphamAb alone did not inhibit the 24 hr LPS induced GRO levels, whereas rrIL-1Ra inhibited the GRO production by 58%. The combination of anti-TNFalpha mAb and rrIL-1Ra inhibited 93% of GRO production. Although treatment with anti-IL-8 IgG inhibited the neutrophil infiltration by 66%, treatment with this antibody did not inhibit GRO production.Taken together, our results suggest that GRO is an essential mediator for neutrophil infiltration in LPS-induced uveitis in rabbits. Most of GRO production is mediated by TNFalpha and IL-1. GRO and IL-8 act in concert to mediate neutrophil infiltration.     

Expression of the chemokines MIP-1alpha, MCP-1, and RANTES in experimental autoimmune uveitis

PURPOSE: To determine the location of the CC chemokines macrophage inflammatory protein (MIP)-1alpha, monocyte chemoattractant protein (MCP)-1, and regulated on activation of normal T-cell-expressed and secreted (RANTES) during disease progression in experimental autoimmune uveitis (EAU) and their relationship with the presence of the T helper cell (Th)1-type cytokine IFNgamma. METHODS: EAU was induced by immunization of Lewis rats with retinal extract. Consecutive cryostat sections were prepared from eyes at different stages of EAU, graded for severity of uveitis and stained by using antibodies to MCP-1, MIP-1alpha, and RANTES and to cell surface markers. Supernatants from superficial cervical lymph node cells were examined by ELISA for IFNgamma, IL-4, and IL-10. RESULTS: MIP-1alpha and IFNgamma were present most frequently and most extensively at peak disease but also were detectable in the choroid 8 days after immunization, before clinical disease onset. MCP-1 and RANTES were present at peak disease, but much less frequently. RANTES was occasionally found in the choroid before clinical disease. By days 19 to 21 after immunization, although infiltrating cells were present, there were only residual low levels of chemokine staining. MCP-1 and RANTES were detected on CD3-positive cells and on some ED1-positive cells, whereas MIP-1alpha was also associated with vessels and areas of exudate. Lymph node cells cultured from animals with peak disease had increased levels of IFNgamma and IL-10, but for IFNgamma this occurred only after stimulation in vitro with retinal extract. CONCLUSIONS: Although MCP-1 and RANTES were associated predominantly with cells infiltrating the retina, MIP-1alpha was also associated with resident cells. All three are likely to exacerbate EAU-MIP-1alpha, to the greatest degree.     

LED光源对人视网膜色素上皮细胞分泌单核细胞趋化因子-1和白细胞介素-8的影响

目的　观察ＬＥＤ光源对人视网膜色素上皮（ｒｅｔｉｎａｌｐｉｇｍｅｎｔｅｐｉｔｈｅｌｉａｌｃｅｌｌｓ,ＲＰＥ）细胞增生及分泌单核细胞趋化因子-１（ｍｏｎｏｃｙｔｅｃｈｅｍｏｔａｃｔｉｃｐｒｏｔｅｉｎ-１,ＭＣＰ-１）和白细胞介素-８（ｉｎｔｅｒｌｅｕｋｉｎ-８,ＩＬ-８）的影响。方法　传代培养的ＡＲＰＥ细胞分别置于５００ｌｕｘ、１０００ｌｕｘ的ＬＥＤ白光、蓝光、绿光中分别照射６ｈ、１２ｈ、２４ｈ,并分别设置对照组避光培养。采用ＭＴＴ法检测ＲＰＥ细胞的增生值（Ａ４６０）,分别使用Ｒｅａｌ-ｔｉｍｅＰＣＲ和ＥＬＩＳＡ法检测各组ＲＰＥ细胞ＭＣＰ-１和ＩＬ-８的表达水平。结果　ＭＴＴ法检测细胞增生值显示:蓝光、白光各组比较差异均有统计学意义（均为Ｐ＜０．０５）,白光５００ｌｕｘ２４ｈ和１０００ｌｕｘ１２ｈ、２４ｈ,蓝光各照度６ｈ、１２ｈ、２４ｈ,ＲＰＥ细胞增生值均较对照组低,差异均有统计学意义（均为Ｐ＜０．０５）,细胞增生值随着白光和蓝光光照强度及光照时间的增加逐渐下降。ＲＴ-ＰＣＲ结果显示,各组ＲＰＥ细胞中ＭＣＰ-１和ＩＬ-８的ｍＲＮＡ比较差异均有统计学意义（均为Ｐ＜０．０５）。其中白光５００ｌｕｘ２４ｈ和１０００ｌｕｘ２４ｈ,蓝光５００ｌｕｘ１２ｈ、２４ｈ和１０００ｌｕｘ１２ｈ、２４ｈ,绿光５００ｌｕｘ２４ｈ和１０００ｌｕｘ２４ｈ,各组ＲＰＥ细胞中ＭＣＰ-１和ＩＬ-８的ｍＲＮＡ表达水平较对照组高,差异均有统计学意义（均为Ｐ＜０．０５）。ＥＬＩＳＡ结果显示,白光５００ｌｕｘ２４ｈ和１０００ｌｕｘ１２ｈ、２４ｈ,蓝光５００ｌｕｘ１２ｈ、２４ｈ和１０００ｌｕｘ１２ｈ、２４ｈ,绿光５００ｌｕｘ２４ｈ、１０００ｌｕｘ２４ｈ,与对照组相比, ＲＰＥ细胞ＭＣＰ-１、ＩＬ-８分泌量增加,差异均有统计学意义（均为Ｐ＜０．０５）;蓝光在５００ｌｕｘ２４ｈ和１０００ｌｕｘ１２ｈ、２４ｈ,ＭＣＰ-１和ＩＬ-８分泌量较白光、绿光增加,差异均有统计学意义（均为Ｐ＜０．０５）。结论　ＬＥＤ白光、蓝光和绿光能以照度和时间依赖性影响ＡＲＰＥ细胞增生及分泌ＭＣＰ-１和ＩＬ-８,以蓝光更为显著。     

Elevated serum IL-8 levels are associated with disease activity in idiopathic intermediate uveitis

AIM—To find a laboratory indicator for systemic involvement in intermediate uveitis.
METHODS—Interleukin 8 (IL-8) and C reactive protein (CRP) serum levels were measured in patients with idiopathic intermediate uveitis (n=61), uveitis controls (n=143), and normal controls (n=29). The records of those with intermediate uveitis were reviewed with the emphasis on disease activity and severity as characterised by the presence of cystoid macular oedema, vitreous exudates or snowbank formation, papillitis, and periphlebitis.
RESULTS—Increased serum IL-8 (20 pg/ml) was found in 27 out of 61 patients with intermediate uveitis (p< 0.01), 12 of 27 patients with sarcoid uveitis (p<0.05), in 19 of 30 patients with HLA-B27 associated acute anterior uveitis (p<0.05), and in five of 29 healthy controls. Raised IL-8 levels in intermediate uveitis were significantly associated with active disease (p<0.001) and the presence of vitreous exudates (p<0.001), papillitis, and periphlebitis (p<0.01). Elevated CRP levels were found in 12 of the 143 uveitis controls but in none of the intermediate uveitis patients or normal controls. During follow up an associated systemic disease was more frequently noticed in patients with an elevated serum IL-8 at entry into the study.
CONCLUSIONS—Elevated IL-8 serum levels were found in patients with active intermediate uveitis of unknown origin. An elevated IL-8 level seems to predispose the patient to a later development of associated systemic disease.

Keywords: C reactive protein; interleukin 8; uveitis; multiple sclerosis; sarcoidosis     

Murine endotoxin-induced uveitis, but not immune complex-induced uveitis, is dependent on the IL-8 receptor homolog.

PURPOSE: To determine the roles of the murine interleukin-8 receptor homolog (mIL-8Rh, neutrophil chemokine CXC receptor 2) and macrophage inflammatory protein-1alpha (MIP-1alpha, a CC chemokine) in two eye inflammation models: endotoxin-induced uveitis (EIU) and immune complex-induced uveitis (reverse passive Arthus reaction (RPAR) uveitis). METHODS: For the EIU model, 250 ng E.coli endotoxin was injected into the vitreous of mIL-8Rh-/- mice or heterozygous littermate mIL-8Rh+/- controls and into MIP-1alpha-/- mice or congenic MIP-1alpha+/+ controls. Eyes were harvested after 24 h for histologic characterization of infiltrating cells and IL-6 bioassays. For the RPAR model, mouse antiserum against human serum albumin (HSA) was injected into the vitreous of mIL-8Rh-/-, mIL-8Rh+/-, MIP-1alpha-/-, and MIP-1alpha+/+ mice. Twenty-four hours later, animals were challenged with intravenous HSA. Eyes were harvested after 4 h for analysis. RESULTS: RPAR resulted in the deposition of immune complexes at the ciliary area and iris with the subsequent development of uveitis. Genetic deficiency of mIL-8Rh reduced the median number of infiltrating cells in EIU by 63% (p < 0.01) but had no effect on RPAR-induced inflammation. In the EIU model, macrophages comprised a much higher percentage (45%) of infiltrating cells in mice lacking mIL-8Rh than in controls (17%). Loss of the MIP-1alpha gene had no apparent effect on RPAR uveitis and a 39% reduction of infiltrating cells in EIU that was not statistically significant. IL-6 activity in aqueous humor was much less in mice with RPAR uveitis than in those with EIU. Neither gene deletion had a significant impact on IL-6 levels in either disease model. CONCLUSIONS: Chemokines acting via mIL-8Rh have a significant role in the induction of neutrophil infiltration during EIU but not during RPAR uveitis. MIP-1alpha is not critical for either EIU or RPAR-induced uveitis. The differential dependence on IL-8-like chemokines is in accord with the two forms ofuveitis having different etiologies and, therefore, potentially different optimal therapies.     

Primary and secondary herpes simplex uveitis in rabbits

Primary and secondary (recurrent) herpes simplex uveitis were studied in the rabbit eye. Intravitreal injection of liver herpes simplex virus (HSV) produced primary uveitis, and reinjection of HSV intravitreally in an eye that had completely recovered from the primary disease produced secondary uveitis. The onset of primary herpes simplex uveitis was gradual, but the secondary disease developed immediately after the intravitreal reinjection. Only live HSV would produce primary uveitis, whereas both inactivated and liver HSV could produce secondary uveitis. Infectious HSV could be isolated from the eye with primary uveitis, but not from the eye with secondary uveitis, a failure that appeared to be due in part to the persistence of anti-HSV neutralizing antibody in the eye after the primary uveitis. The results suggest that primary uveitis is caused by infection of the uveal tissue by live HSV, and that secondary uveitis is caused by HSV-induced immunological mechanisms.     

Effects of L-NAME and timolol on aqueous IL-1beta,IL-6, IL-8, TNF-alpha and NO levels after Nd:YAG laser iridotomy in rabbits

PURPOSE: Pro-inflammatory cytokines are produced by tissues and play a vital role in the host inflammatory response and uveitis. Nitric oxide (NO) can be produced in large amounts as a response to experimentally-induced uveitis or cytokines. In this study, we measured the levels of pro-inflammatory cytokines such as interleukin (IL)-1beta, IL-6, IL-8, tumor necrosis factor (TNF)-alpha and free-radical in aqueous humor after Nd:YAG laser iridotomy in rabbits, and investigated whether timolol maleate an anti-glaucoma drug, or a NO synthase inhibitor, NG-nitro-L-arginine methyl esther (L-NAME) had an inhibitory effect on these molecules, since L-NAME is a known anti-inflammatory agent in rabbits. METHODS: Bilateral experimental Nd:YAG laser iridotomy (power 7.5 mJ, mode single burst, aiming beam 4) was performed on 18 rabbits under general plus topical anesthesia. Aqueous humor samples were taken by clear corneal paracentesis preoperatively, and 1 and 24 h postoperatively. Six rabbits (12 eyes) were given bilateral topical timolol maleate 0.5% (Timoptic) drop b.i.d. (group 1), six rabbits (12 eyes) received bilateral 0.1 ml subconjuntival injections of L-NAME (150 mg/kg) (group 2), and six rabbits (12 eyes) were treated with topical balanced salt solution (BSS) b.i.d. (control). RESULTS. Preoperative cytokine and NO levels were comparable in the three groups, with no significant differences. In addition, there was no significant difference in baseline cytokine levels between the right and left eyes. In all groups, pre- and postoperative mean IL-1beta levels were below the detection limit of the assay (<5.0 pg/ml). In the control group, postoperative mean IL-6, IL-8 and NO levels were significantly higher after Nd:YAG laser iridotomy than before (for each, p < 0.01). Timolol and L-NAME both inhibited the rise in IL-8 and TNF-alpha levels. Timolol also inhibited the rise in IL-6 but not NO. L-NAME had an inhibitory effect against NO, but not IL-6. CONCLUSIONS: L-NAME has an inhibitory effect on IL-8, TNF-alpha and NO, but not on IL-6. Timolol had inhibitory effects on IL-6, IL-8 and TNF-alpha, but not on NO. These preliminary experimental results might help in assssing the effect of Nd:YAG laser iridotomy in aqueous humor, and to understand the inhibitory effects of timolol and L-NAME against these molecules.     

MCP-1基因-2518A/G多态性与葡萄膜炎易感性的Meta分析

背景 近年来研究表明,单核细胞趋化蛋白1(MCP-1)基因多态性与葡萄膜炎易感性密切相关,然而目前国内外关于MCP-1基因-2518A/G多态性与葡萄膜炎发病风险的相关性尚未有一致结论.目的 系统评价MCP-1基因-2518 A/G多态性与葡萄膜炎易感性的关系.方法 按照检索策略,计算机检索PubMed、Embase、Web of Science、中国知网(CNKI)、维普网(VIP)、万方数据及中国生物医学文献数据库(CBD),检索时限为建库起至2014年3月,收集关于MCP-1基因-2518A/G多态性与葡萄膜炎发病风险的相关文献,按照纳入及排除标准筛选文献、提取数据资料,并对纳入研究的文献进行质量评价.采用RevMan 5.2及Stata12.0软件进行Meta分析,计算合并效应量优势比(OR)值及其95％可信区间(CI),并进行发表偏倚及敏感性分析.结果 共纳入8篇研究文献,累积病例1 197例,对照1 570例.MCP-1基因-2518A/G G和A、GG和AA及GG和AG+AA基因型与总体葡萄膜炎发病风险均无明显相关性(均P＞0.05),GG+AG和AA基因型与总体葡萄膜炎发病风险具有显著相关性(P=0.01,OR=1.25,95％C1:1.06～1.48),而敏感性分析结果显示二者无明显相关性(P=0.19,OR=1.16,95％ CI:0.93～1.45).按葡萄膜炎类型进行亚组分析结果显示,携带等位基因G、GG基因型的个体罹患前葡萄膜炎的风险明显增高(G和A:P=0.01,OR=1.49,95％CI:1.16 ～1.90;GG和AA:P=0.01,OR=2.09,95％CI:1.21～3.61;GG+AG和AA:P=0.01,OR=1.58,95％ CI:1.12～2.23;GG和AG+AA:P=0.01,OR=1.78,95％CI:1.12 ～2.83),且GG+AG和AA基因型个体罹患白塞病的风险也明显增高(P=0.04,OR=1.35,95％CI:1.01～1.79),而与其他类型葡萄膜炎发病风险无明显相关(P＞0.05).按种族进行亚组分析结果显示,在黄种人群中,携带等位基因G、GG基因型的个体罹患葡萄膜炎的风险明显增高(G和A:P=0.04,OR=1.15,95％CI:1.01～1.32;GG和AA:P=0.04,OR=1.32,95％ CI:1.02 ～1.71;GG+AG和AA:P=0.01,OR=1.36,95％CI:1.09～1.70),而在白种人群中等位基因G、GG基因型与葡萄膜炎均无明显相关(均P＞0.05).结论 MCP-1基因-2518A/G多态性与白塞病、前葡萄膜炎及黄种人群葡萄膜炎易感性有关,GG基因型及等位基因G可能是白塞病、前葡萄膜炎及黄种人群葡萄膜炎易感的危险因素.