Treatment of experimental autoimmune uveoretinitis with atorvastatin and lovastatin

Can Simvastatin Reduce the Need for Immunomodulatory Drugs to Treat Uveitis?: A Prospective, Randomized, Placebo-Controlled Trial

Objective

To assess the efficacy of simvastatin 80 mg/day versus placebo in patients with noninfectious nonanterior uveitis receiving prednisolone ≥ 10 mg/day.

Design

Randomized, double-masked, controlled trial.

Subjects

Adult patients with noninfectious nonanterior uveitis on oral prednisolone dose of ≥ 10 mg/day.

Methods

Patients were randomly assigned at a 1:1 ratio to receive either simvastatin 80 mg/day or placebo. A total of 32 patients were enrolled (16 in each arm), all of whom completed the primary end point, and 21 reached the 2-year visit (secondary end points).

Main Outcome Measures

The primary end point was mean reduction in the daily prednisolone dose at 12 months follow-up. Secondary end points were mean reduction in prednisolone dose at 24 months, percent of patients with a reduction in second-line immunomodulatory agents, time to disease relapse, and adverse events.

Results

Our results show that simvastatin 80 mg/day did not have a significant corticosteroid-sparing effect at 12 months (estimate: 3.62; 95% confidence interval [CI]: -8.15 to 15.38; P = 0.54). There was no significant difference between the groups with regard to prednisolone dose or change in dose at 12 and 24 months. There was no difference between the 2 groups in percent of patients with reduction in second-line agent by 24 months. Among patients who achieved disease quiescence, the median time to first relapse was longer for those receiving simvastatin (38 weeks, 95% CI: 14-54) than placebo (14 weeks, 95% CI: 12-52), although this was not statistically significant. There was no significant difference in adverse events or serious adverse events between the 2 groups.

Conclusions

Simvastatin 80 mg/day did not have an effect on the dose reduction of corticosteroids or conventional immunomodulatory drugs at 1 and 2 years. The results suggest that it may extend the time to disease relapse among those who achieve disease quiescence.

Financial Disclosures

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Effects of atorvastatin on the function of Tenon's capsule fibroblasts in human eyes

PURPOSE

This study aimed to explore the role of atorvastatin (ATO) in the prevention and treatment of the scarring of filtration channels after glaucoma surgery.

METHODS

Human Tenon's capsule fibroblasts (HTFs) were co-cultured with various concentrations of ATO. First, Cell Counting Kit-8 assay was performed to evaluate the effects of various concentrations of ATO on the viability of HTFs. Then, after the ATO stimulated the HTFs for 24 h, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay was performed to evaluate the apoptosis of HTFs. Transwell assay was also performed to evaluate the migration of HTFs. Moreover, enzyme-linked immunosorbent assay (ELISA) was performed to detect the protein expression levels of transforming growth factor-β1 (TGF-β1) and TGF-β2 in the cell culture supernatant of HTFs. Western blot was carried out to detect the protein expression levels of smooth muscle actin (SMA), p38, Smad3, fibronectin, collagen I and collagen III in different groups.

RESULTS

The results revealed that ATO could inhibit the proliferation and migration of HTFs. Based on the TUNEL assay, 100 μM and 150 μM ATO could induce cell apoptosis. The ELISA results indicated that ATO could down-regulate the expression level of TGF-β2, and western blot analysis revealed that the protein expression levels of SMA, p38, Smad3, fibronectin, collagen I and collagen III in the TGF-β2 group were all up-regulated compared with the control group, whereas the addition of ATO could reverse this up-regulation.

CONCLUSIONS

ATO could inhibit the proliferation and migration of HTFs and induce their apoptosis. It was preliminary proven that ATO could inhibit the signaling pathway induced by TGF-β. It is suggested that ATO could be a basis for the treatment of the scarring of filtration channels after glaucoma surgery.

Combined Therapy of Experimental Autoimmune Uveitis by a Dual-Drug Nanocomposite Formulation with Berberine and Dexamethasone

Purpose

Autoimmune uveitis is a kind of sight-threatening ocular and systemic disorders. Recent treatments on autoimmune uveitis still remain many limitations due to extreme complexity and undetermined pathogenesis. In this study, a novel dual-drug nanocomposite formulation is developed to treat experimental autoimmune uveitis by a combined and sustained therapy method.

Methods

The dual-drug nanocomposite formulation is constructed by integrating berberine (BBR)-loaded mesoporous silica nanoparticles (MSNs) into dexamethasone (DEX)-loaded thermogel (BBR@MSN-DEX@Gel). The BBR@MSN-DEX@Gel is characterized by transmission electron microscopy, dynamic light scattering, Fourier transform infrared spectrometer and rheometer. The in vitro drug release profile, cytotoxicity and anti-inflammation effectiveness of BBR@MSN-DEX@Gel on lipopolysaccharide-stimulated human conjunctival epithelial cells are investigated. After the in vivo drug release profile and biosafety of the dual-drug nanocomposite formulation are confirmed, its treatment effectiveness is fully assessed based on the induced experimental autoimmune uveitis (EAU) Lewis rat's model.

Results

The dual-drug nanocomposite formulation has good injectability and thermosensitivity, suitable for administration by an intravitreal injection. The BBR@MSN-DEX@Gel has been found to sustainably release both drugs for up to 4 weeks. The carrier materials have minimal in vitro cytotoxicity and high in vivo biosafety. BBR@MSN-DEX@Gel presents obviously anti-inflammatory effectiveness in vitro. After administration of BBR@MSN-DEX@Gel into Lewis rat's eye with EAU by an intravitreal injection, the nanocomposite formulation significantly suppresses inflammatory reaction of autoimmune uveitis via a dual-drug combined and sustained therapy method, compared with the equivalent dose of single-component formulations.

Conclusion

BBR@MSN-DEX@Gel serves as a promising dual-drug nanocomposite formulation for future treatment of autoimmune uveitis.

Decreased risk of non-infectious anterior uveitis with statin therapy in a large healthcare claims database

PURPOSE

The purpose of this study is to determine if statin therapy decreases the incidence of non-infectious uveitis (NIU) using a retrospective cohort study.

METHODS

Patients enrolled in a national insurance plan who initiated statin (n = 711,734, statin cohort) or other lipid-lowering therapy (n = 148,044, non-statin cohort) were observed for NIU development. Incident NIU in the primary analysis was defined as a new diagnosis code for NIU followed by a second instance of a NIU code within 120 days. For the secondary outcome definition, a corticosteroid prescription or code for an ocular corticosteroid injection within 120 days of the NIU diagnosis code was used instead of the second NIU diagnosis code. Estimation of NIU incidence used multivariable Cox proportional hazards regression. The proportional hazards assumption was satisfied by creating two time periods of analysis, ≤ 150 and > 150 days. Subanalyses were performed by anatomic subtype.

RESULTS

Overall, the primary outcome occurred 541 times over 690,465 person-years in the statin cohort and 103 times over 104,301 person-years in the non-statin cohort. No associations were seen in the ≤ 150-day analyses (p > 0.20 for all comparisons). However, after 150 days, the statin cohort was less likely to develop any uveitis [hazard ratio (HR) = 0.70, 95% confidence interval (CI): 0.51-0.97, P = 0.03] in the primary outcome analysis, but did not meet significance for the secondary outcome (HR = 0.85, 95% CI: 0.63-1.15, P = 0.30). Similarly, in the anatomic subtype analysis, after 150 days, the statin cohort was less likely to develop anterior uveitis (HR = 0.67, 95% CI: 0.47-0.97, P = 0.03) in the primary analysis, but the association did not reach significance for the secondary outcome (HR = 0.82, 95% CI: 0.56-1.20, P = 0.31).

CONCLUSION

Our results suggest that statin therapy for > 150 days decreases the incidence of NIU.

Remission of Non-Infectious Anterior Scleritis: Incidence and Predictive Factors

PURPOSE

To assess how often non-infectious anterior scleritis remits and identify predictive factors.

METHODS

Our retrospective cohort study at four ocular inflammation subspecialty centers collected data for each affected eye/patient at every visit from center inception (1978, 1978, 1984, 2005) until 2010. Remission was defined as inactivity of disease off all suppressive medications at all visits spanning at least three consecutive months or at all visits up to the last visit (to avoid censoring patients stopping follow-up after remission). Factors potentially predictive of remission were assessed using Cox regression models.

RESULTS

During 1,906 years' aggregate follow-up of 832 affected eyes, remission occurred in 214 (170 of 584 patients). Median time-to-remission of scleritis = 7.8 years (95% confidence interval [CI]: 5.7, 9.5). More remissions occurred earlier than later during follow-up. Factors predictive of less scleritis remission included scleritis bilaterality (adjusted hazard ratio [aHR] = 0.46, 95% CI: 0.32-0.65); and diagnosis with any systemic inflammatory disease (aHR = 0.36, 95% CI: 0.23-0.58), or specifically with Rheumatoid Arthritis (aHR = 0.22), or Granulomatosis with Polyangiitis (aHR = 0.08). Statin treatment (aHR = 1.53, 95% CI: 1.03-2.26) within ≤90 days was associated with more remission incidence.

CONCLUSIONS

Our results suggest scleritis remission occurs more slowly in anterior scleritis than in newly diagnosed anterior uveitis or chronic anterior uveitis, suggesting that attempts at tapering suppressive medications is warranted after long intervals of suppression. Remission is less frequently achieved when systemic inflammatory diseases are present. Confirmatory studies of whether adjunctive statin treatment truly can enhance scleritis remission (as suggested here) are needed.

Chitosan-Coated PLGA Nanoparticles for Enhanced Ocular Anti-Inflammatory Efficacy of Atorvastatin Calcium

Background

Atorvastatin calcium (AT) is an ocular anti-inflammatory with limited bioavailability when taken orally due to its low solubility in low pH and extensive first-pass effect. To overcome these problems, AT was entrapped in polymeric nanoparticles (NPs) to improve surface properties and sustained release, in addition to achieving site-specific action.

Methods

AT was entrapped in chitosan (CS)-coated polylactic-co-glycolic acid (PLGA) NPs to form AT-PLGA-CS-NPs (F1). F1 and free AT were embedded in thermosensitive Pluronic^®127-hydroxypropyl methylcellulose (HPMC) to form thermosensitive gels (F2) and (F3) while F4 is AT suspension in water. F1 was assessed for size, surface charge, polydispersity index (PDI), and morphology. F2 and F3 were examined for gelation temperature, gel strength, pH, and viscosity. In vitro release of the four formulations was also investigated. The ocular irritancy and anti-inflammatory efficacy of formulations against prostaglandin E₁-(PGE₁) induced ocular inflammation in rabbits were investigated by counting the polymorphonuclear leukocytes (PMNs) and protein migrated in tears.

Results

Oval F1 of 80.0–190.0±21.6 nm exhibited a PDI of 0.331 and zeta potential of ‏17.4±5.62 mV with a positive surface charge. F2 and F3 gelation temperatures were 35.17±0.22°C and 36.93±0.31°C, viscosity 12,243±0.64 and 9759±0.22 cP, gel strength 15.56±0.6 and 12.45±0.1 s, and pHs of 7.4±0.02 and 7.4±0.1, respectively. In vitro release of F1, F2, F3, and F4 were 48.21±0.31, 26.48±0.5, 84.76±0.11, and 100% after 24 hrs, respectively. All formulations were non-irritant. F2 significantly inhibited lid closure up to 3 h, PMN counts and proteins in tear fluids up to 5 h compared to other formulations.

Conclusion

AT-PLGA-CS-NP thermosensitive gels proved to be successful ocular anti-inflammatory drug delivery systems.

Statins in ophthalmology

Statins, 3-hydroxy-3-methyl-gutaryl coenzyme A reductase inhibitors, are a class of lipid-lowering drugs with anti-inflammatory, immunomodulatory, and vascular effects. Statins are increasingly being used in the treatment of a variety of medical conditions. We examine the actions of statins on the eye and its associated ophthalmic disorders. Statins can be synthetic or nonsynthetic, and their differentiating derivations may contribute to their varying cholesterol-lowering and pleiotropic effects. There is conflicting evidence on the ocular therapeutic and adverse effects of the statins. Statins may play a role in reducing the burden of dry eye, corneal ulcer scarring, thyroid-associated orbitopathy, glaucoma, uveitis and other associated ocular inflammatory states, cataract, proliferative vitreoretinopathy, diabetic retinopathy, macular degeneration, and choroidal melanoma. Topical preparations of statins can be formulated, thereby extending the range of ocular diseases that may be amenable to treatment. Statins have a relatively safe side effect profile, but rare and serious adverse reactions have been reported with their usage in ophthalmology, including myopathies and rhabdomyolysis with acute renal failure.

Immunotropic Effects and Proposed Mechanism of Action for 3-Hydroxy-3-methylglutaryl-coenzyme A Reductase Inhibitors (Statins)

Inhibitors of HMG-CoA reductase (statins) are the major group of lipid-lowering drugs. Along with hypocholesterolemic activity, statins exhibit anti-inflammatory and immunomodulatory properties that expand their clinical use, particularly, in the treatment of chronic inflammatory and autoimmune disorders. In this review, we critically analyze the data of statin effects on immune cells (e.g., monocytes and T cells) involved in the development of atherosclerosis and other chronic inflammatory diseases. We (i) discuss the properties of statins and routes of cell entry, as well as their major intracellular targets; (ii) evaluate the data on the effects of statins on the subset composition of circulatory monocytes, ability of monocytes to migrate to the site of inflammation (cell motility and expression of adhesion molecules and chemokine receptors), production of cytokines, matrix metalloproteinases, and reactive oxygen species by monocytes/macrophages, and antigen-presenting activity in peripheral blood monocyte-derived dendritic cells; and (iii) summarize the data on the regulation of proliferation and differentiation of various CD4+ T cell subsets (type 1/2/17 helper T cells and regulatory T cells) by statins.

'Statins in retinal disease'

Statins are known for their blood cholesterol-lowering effect and are widely used in patients with cardiovascular and metabolic diseases. Research over the past three decades shows that statins have diverse effects on different pathophysiological pathways involved in angiogenesis, inflammation, apoptosis, and anti-oxidation, leading to new therapeutic options. Recently, statins have attracted considerable attention for their immunomodulatory effect. Since immune reactivity has been implicated in a number of retinal diseases, such as uveitis, age-related macular degeneration (AMD) and diabetic retinopathy, there is now a growing body of evidence supporting the beneficial effects of statins in these retinopathies. This review evaluates the relationship between statins and the pathophysiological basis of these diseases, focusing on their potential role in treatment. A PubMed database search and literature review was conducted. Among AMD patients, there is inconsistent evidence regarding protection against development of early AMD or delaying disease progression; though they have been found to reduce the risk of developing choroidal neovascular membranes (CNV). In patients with retinal vein occlusion, there was no evidence to support a therapeutic benefit or a protective role with statins. In patients with diabetic retinopathy, statins demonstrate a reduction in disease progression and improved resolution of diabetic macular oedema (DMO). Among patients with uveitis, statins have a protective effect by reducing the likelihood of uveitis development.

Fisetin inhibits liver cancer growth in a mouse model: Relation to dopamine receptor

Fisetin (3,3',4',7-tetrahydroxyflavone), a natural abundant flavonoid, is produced in different vegetables and fruits. Fisetin has been reported to relate to various positive biological effects, including anti-proliferative, anticancer, anti-oxidative and neuroprotective effects. Dopamine receptors (DRs) belonging to G protein‑coupled receptor family, are known as the target of ~50% of all modern medicinal drugs. DRs consist of various proteins, functioning as transduction of intracellular signals for extracellular stimuli. We found that fisetin performed as DR2 agonist to suppress liver cancer cells proliferation, migration and invasion. Caspase-3 signaling was activated to induce apoptosis for fisetin administration. Furthermore, TGF‑β1 was also inhibited in fisetin-treated liver cancer cells, reducing epithelial-mesenchymal transition (EMT). Additionally, fisetin downregulated VEGFR1, p-ERK1/2, p38 and pJNK, ameliorating liver cancer progression. In vivo, the orthotopically implanted tumors from mice were inhibited by fisetin adminisatration accompanied by prolonged survival rate and higher levels of dopamine. Together, the results indicated a novel therapeutic strategy to suppress liver cancer progression associated with DR2 regulation, indicating that dopamine might be of importance in liver cancer progression.

Treatment of experimental autoimmune uveoretinitis with different natural compounds

Uveitis is an important eye disease that potentially causes loss of sight. Although extensive studies have been conducted on uveitis, the exact pathogenesis remains to be determined. The effects of treatment with natural compounds on an experimental autoimmune uveoretinitis (EAU) rat model were examined in the present study. A total of 25 rats were divided into 5 groups: Alkaloids (n=5), saponins (n=5), flavonoids (n=5), phenols (n=5), and the normal saline group (n=5). The rats in each group were treated with an intraperitoneal injection of proper alkaloids (berberine hydrochloride), saponins (steroidal saponins), flavonoids (baicalein), or phenols (chlorogenic acid) or physiological saline, respectively. The rats' aqueous humour and crystalline lens was then observed under the slit lamp periodically, looking for signs of inflammation. After 2 weeks, the rats were sacrificed and the degree of pathological changes on their eyeballs under different treatment methods were determined using an optical microscope. The expression of the interleukin (IL)‑17 gene in the ocular tissues of the rats was assessed via RT‑PCR and western blot analysis. Apoptosis on the rats' retinal tissues was detected using flow cytometry. The results showed that rats injected with phenols (chlorogenic acid) had serious ocular vascular dilatation, iris hemorrhage and purulent exudation; those injected with alkaloids (berberine hydrochloride) and flavonoids (baicalein) had a more mild form of inflammation; and those administered saponins (steroidal saponins) had only mild inflammation signs. Following detection of IL‑17 mRNA and protein expression levels in the ocular tissues of rats of the five groups, it was found that their expression was lowest in the saponin‑treated group and the other differences in expression were all statistically significant (P<0.05). A comparison with other groups revealed that cell apoptosis in the eyes of rats in the saponin group was the most prominent, reflecting a beneficial decrease in the amount of inflammatory cells on the lesion. Based on these findings, natural compounds such as saponins (steroidal saponins), alkaloids (berberine hydrochloride), and flavonoids (baicalein), but not phenols (chlorogenic acid), can inhibit the clinical symptoms of EAU in rats to a certain extent and reduce cell apoptosis. The most promising results in the present study were obtained using steroidal saponins.

Association between statin use and uveitis: results from the Pacific Ocular Inflammation study

PURPOSE

To assess whether there is a protective association between statin use and uveitis diagnosis.

DESIGN

Retrospective, population-based case-control study.

METHODS

Medical records of all patients in the Kaiser Permanente Hawaii health plan between January 1, 2006 and December 31, 2007 (N = 217 061) were searched electronically for International Classification of Diseases, 9th Revision, diagnosis codes related to uveitis. Chart review was done to confirm incident uveitis diagnosis during the study period. Two control groups were each randomly selected at a 5:1 ratio to cases, and controls were assigned an index date to match their respective case diagnosis date. One control group was selected from the general Kaiser Permanente Hawaii population that had at least 1 healthcare visit during the study period. Another control group was selected from the population of Kaiser Permanente Hawaii members who had at least 1 visit to the ophthalmology clinic during the study period. Statin use was defined as filling a prescription for statin medication in the year prior to the diagnosis or index date based on an electronic search of the Kaiser Permanente Hawaii pharmacy database for Generic Product Identification codes. A conditional logistic regression model with clinical diagnosis of uveitis as the outcome was used to assess the relationship between statin use and uveitis.

RESULTS

One hundred eight incident cases of uveitis were identified. Nineteen percent of uveitis patients had used statin medication in the year prior to diagnosis compared to 30% of patients in the general Kaiser population control (P = .03) and 38% of patients in the ophthalmology clinic control (P < .001). Using the general Kaiser population control and adjusting for age, sex, race, and autoimmune diseases, the odds of a statin user developing uveitis were 48% less than the odds of a non-statin user developing uveitis (OR: 0.52, 95% CI: 0.29-0.94, P = .03). Similarly, the odds of developing uveitis were 33% less for statin users compared to non-statin users (OR: 0.67, 95% CI: 0.38-1.19, P = .17) when adjusting for these factors and using the ophthalmology clinic control group.

CONCLUSIONS

Statin use may be protective against the development of uveitis. Several anti-inflammatory and immunomodulatory mechanisms may explain this association.

Role of statins in the treatment of multiple sclerosis

Statins as inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase are widely prescribed for hypercholesterolemia treatment. In the last years, statins have also been shown to exert immunomodulatory and anti-inflammatory effects which appear to be related to inhibition of isoprenylation of small GTP-binding proteins and, at least in part, independent of their cholesterol-lowering effects. These "pleiotropic" effects make statins an attractive treatment option for immune-mediated disorders such as multiple sclerosis. Studies in vitro and in experimental autoimmune encephalomyelitis animal model seem to support not only the efficacy of statins as immunomodulatory agents but also their potential neuroprotective properties, although the exact mechanism with which statins exert these effects has not yet been fully understood. The immunomodulatory, anti-inflammatory and neuroprotective properties of statins provided the incentive for several clinical trials in multiple sclerosis, in which they were tested not only as mono-therapy but also in combination with interferon-β. However, the attempt to translate the results of animal model studies in humans produced conflicting results. Further large, prospective, randomized, double-blind, placebo-controlled trials, designed to evaluate the long-term effects of statins alone or in add-on to other disease-modifying therapies, are needed to support their routine clinical use in multiple sclerosis.

Statin Modulation of Human T-Cell Proliferation, IL-1β and IL-17 Production, and IFN-γ T Cell Expression: Synergy with Conventional Immunosuppressive Agents

HMG-CoA reductase inhibitors (statins) have been demonstrated to be immunomodulatory for human immune-mediated disease and in experimental models. The aim of this study was to compare statin-mediated immunosuppressive effects on human T-cell responses in vitro with those of conventional immunosuppressives (dexamethasone, cyclosporin A (CsA), mycophenolate, and rapamycin). Statins (atorvastatin, lovastatin, and simvastatin) were investigated for their modulatory effects on human PBMC viability, cytokine profiles, and T-cell proliferation. At concentrations that inhibited anti-CD3/28-stimulated T-cell proliferation (P < 0.01), simvastatin significantly decreased intracellular CD4(+) T-cell expression of IFN-γ (P < 0.01) to levels similar to those induced by conventional immunosuppressives. Atorvastatin and lovastatin also decreased IFN-γ expression, although to a lesser degree (P < 0.05). All three statins reduced levels of IL-17 production (P < 0.01). However, in response to anti-CD3/28 stimulation, simvastatin significantly upregulated IL-1β production (P < 0.05). The profile of cytokines produced in response to anti-CD3/28 stimulation was similar when both atorvastatin and dexamethasone were added as compared with dexamethasone alone, suggesting that atorvastatin can synergise with dexamethasone with respect to immunomodulation of cytokines. This data supports the hypothesis of selective statin-mediated immunomodulatory effects on human immune cells.

β-Arrestins as potential therapeutic targets for Alzheimer's disease

β-arrestins represent a small family of G protein-coupled receptors (GPCRs) regulators, which provide modulating effects by facilitating desensitization and internalization of GPCRs as well as initiating their own signalings. Recent reports have demonstrated that β-arrestins levels were correlated with amyloid-β peptide (Aβ) pathology in brains of Alzheimer's disease (AD) patients and animal models. β-arrestins could enhance the activity of γ-secretase via interacting with anterior pharynx defective 1 subunit, which increased Aβ production and contributed to the pathogenesis of AD. In addition, Aβ-induced internalization of β2-adrenergic receptor internalization and loss of dendritic spine in neurons were proven to be mediated by β-arrestins, further establishing their pathogenic role in AD. More importantly, deletion of β-arrestins markedly attenuated AD pathology, without causing any gross abnormality. Here, we review the evidence about the roles of β-arrestins in the progression of AD. In addition, the established and postulated mechanisms by which β-arrestins mediated in AD pathogenesis are also discussed. Based on the role of β-arrestins in AD pathogenesis, genetically or pharmacologically targeting β-arrestins might provide new opportunities for AD treatment.

Statin use and ocular inflammatory disease risk

Background

This study aims to evaluate the effect of oral statin medication use on the subsequent development of ocular inflammatory disease (OID). A retrospective nested case–control study was carried out on patient records from the Birmingham Veterans Affairs Medical Center. All male patients with a new diagnosis of OID over a 5-year period were included. Ten control subjects (without OID) were age-matched to each OID case. Prescription files of all subjects were queried for statin use. Information on selected comorbid medical conditions was also obtained. Conditional logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for risk of OID development in the context of statin use, controlling for comorbid conditions.

Results

Ninety-two incident cases of OID were identified. A trend toward a reduction in the risk of new OID development was found in patients that used statins compared to those that did not (OR 0.50, 95% CI 0.20 to 1.23, p = 0.13). The longer the duration of statin use, the greater is the effect.

Conclusions

Use of oral statins may be associated with a reduced risk for the development of OID. This reduced risk increases with increasing duration of use. Larger clinical studies would be required to definitively establish the effectiveness of statins in lowering the incidence of OID.

Immunomodulation by statins: mechanisms and potential impact on autoimmune diseases

Statins are inhibitors of the enzyme 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) and they are the most effective agents for lowering cholesterol in clinical practice for the treatment of cardiovascular diseases. However, it has become clear that statins also have pleiotropic immunomodulatory effects in addition to their lipid-lowering properties. As a result, much attention has been focused on their potential as therapeutic agents for the treatment of inflammatory autoimmune diseases. In this review the effect of statins on the expression and function of a variety of immune-relevant molecules will be discussed alongside the underlying mechanisms that contribute to the immunomodulatory effects of statins.

Staphylococcal enterotoxin B is involved in aggravation and recurrence of murine experimental autoimmune uveoretinitis via Vbeta8+CD4+ T cells

Endogenous uveitis is a common cause of visual disability and blindness. The etiology of uveitis remains largely unknown but reasonable etiologic factors include infections. Superantigens are regarded as one of the leading causes of infectious etiology in autoimmune disease. However, the role of superantigens in uveitis remains unclear. In the present study, we investigated the effect of Staphylococcal enterotoxin B (SEB), a member of the superantigens, using an experimental model of autoimmune uveoretinitis (EAU). C57BL/6 mice were immunized with human interphotoreceptor retinoid binding protein (IRBP) peptide, and the severity of EAU disease was scored. Vehicle (PBS) alone or SEB dissolved in PBS was administered by intravenous injection on post-immunization day 10 or on post-immunization day 24. In addition, a systemic immune response study was performed to address the effects of SEB on systemic immunity. EAU was aggravated significantly by the injection of SEB at post-immunization day 10. Furthermore, relapse was induced by the injection of SEB at day 24. On the other hand, SEB injection without IRBP peptide immunization elicited no inflammatory changes in the uvea or retina. Furthermore, SEB enhanced not only the IRBP-specific T-cell proliferative responses but also IFN-gamma and IL-17 production. Moreover, the intraocular expression levels of these cytokines was also enhanced by SEB injection. Both anti-CD4 and -Vbeta8 Ab administration suppressed disease aggravation and the enhancement of IRBP-specific T-cell responses caused by SEB. These results suggest that SEB is involved significantly in the aggravation or recurrence of endogenous uveitis through activation of autoreactive uveitogenic T cells.

Role of DAF in protecting against T-cell autoreactivity that leads to experimental autoimmune uveitis

PURPOSE

To investigate the role of decay-accelerating factor (DAF), a cell surface complement regulator that recently has been linked to T-cell responses and autoimmunity in the pathogenesis of experimental autoimmune uveitis (EAU).

METHODS

EAU was induced in wild-type (WT) and Daf1(-/-) mice, and their disease severities, IRBP specific Th1/Th17 responses, and cytokine expression profiles were compared. In a test of the efficacy of treatment with soluble mouse DAF protein, EAU was induced in disease-susceptible B10.RIII mice, and they were treated with 0.5 mg soluble DAF protein or equal volume of PBS IP every other day. Retinal histology and IRBP-specific T-cell responses were compared after 14 days.

RESULTS

Both EAU incidence and histopathology scores were significantly greater in Daf1(-/-) mice. There was a >10-fold greater mononuclear cell influx into the retina together with severe vasculitic lesions, retinal folding, and photoreceptor cell layer destruction. There were 5- to 7-fold greater Th1 and 3- to 4-fold greater Th17 responses against IRBP in Daf1(-/-) mice with EAU, and they expressed significantly elevated levels of GM-CSF, IL-2, IL-3, and IFN-gamma. WT B10.RIII mice that received soluble DAF protein treatments exhibited decreased IRBP-specific Th1/Th17 responses and were protected from retinal injury compared with the mice that received PBS treatments.

CONCLUSIONS

DAF significantly influences IRBP-specific Th1 and Th17 responses and disease severity in EAU. Systemic upregulation of DAF levels could be used to suppress retinal antigen(s)-specific autoimmunity to treat autoimmune posterior uveitis.

Glucocorticoids regulate innate immunity in a model of multiple sclerosis: reciprocal interactions between the A1 adenosine receptor and beta-arrestin-1 in monocytoid cells

Desensitization of seven transmembrane receptors (7TMRs), which are modulated by the beta-arrestins, leads to altered G protein activation. The A1 adenosine receptor (A1AR) is an antiinflammatory 7TMR exhibiting reduced expression and activity in both multiple sclerosis (MS) and the murine MS model, experimental autoimmune encephalomyelitis (EAE) in monocytoid cells. Herein, we report that beta-arrestin-1 expression was increased in brains of MS patients relative to non-MS brains, whereas A1AR expression was concomitantly reduced. This inverse relationship between beta-arrestin-1 and A1AR was confirmed in cultured monocytoid cells as beta-arrestin-1 overexpression resulted in a down-regulation of A1AR together with the internalization of the surface receptor. Moreover, a physical interaction between beta-arrestin-1 and A1AR was demonstrated in monocytoid cells. Proinflammatory cytokines regulated the A1AR/beta-arrestin-1 interactions, while A1AR activation also modulated proinflammatory cytokines expression. During EAE, beta-arrestin-1 and A1AR expression in the spinal cord displayed a similar pattern compared to that observed in MS brains. EAE-induced neuroinflammation and neurobehavioral deficits were suppressed by glucocorticoid treatments, accompanied by concurrent reduced beta-arrestin-1 and enhanced A1AR expression. Thus, the interplay between beta-arrestin-1 and A1AR in the central nervous system during neuroinflammation represents a reciprocal regulatory mechanism through which neuroprotective therapeutic strategies for neuroinflammatory diseases might be further developed.