Uveitis: Advances in understanding of pathogenesis and treatment

Steroidal nanoformulations for the treatment of uveitis: potential, promises and future perspectives

BACKGROUND

Intraocular inflammation, commonly referred to as uveitis, is a prevalent ocular disease. The categorization of uveitis may be based on the prevailing anatomical site, which includes anterior, intermediate, and posterior uveitis. There exists a significant body of evidence indicating that T cells play a pivotal role in the pathogenesis of autoimmune uveitis. In addition to the presence of T cells, an elevation in levels of inflammatory cytokines and a reduction in regulatory cytokines were also noted. The primary pharmacological interventions for uveitis comprise of corticosteroids, methotrexate, anti-vascular endothelial growth factor (VEGF) agents, anti-tumor necrosis factor-alpha (TNF-α) antibodies, and sirolimus. These medications offer prompt alleviation for inflammation. Nevertheless, prolonged administration of corticosteroids invariably leads to unfavorable adverse reactions. The traditional topical corticosteroids exhibit certain limitations, including inadequate transcorneal permeation and low corneal retention, leading to reduced ocular bioavailability. Consequently, there is a growing inclination towards the creation of innovative steroid drug delivery systems with the aim of reducing the potential for adverse effects, while simultaneously enhancing the drug's corneal permeation and retention.

CONCLUSION

This review is an attempt to compile all the research work done so far in this field and provides a brief overview of the global efforts to develop innovative nanocarrier-based systems for corticosteroids.

Ocular Inflammation Post-Vaccination

The association between vaccines and ocular disorders has attracted significant attention in scientific research. Numerous mainstream vaccines are associated with a range of uveitis types, including anterior, intermediate, and posterior uveitis. Additionally, they are associated with distinct ocular diseases such as multifocal choroiditis, Vogt-Koyanagi-Harada (VKH) disease, acute posterior multifocal placoid pigment epitheliopathy (APMPPE), and multiple evanescent white dot syndrome (MEWDS). These ocular conditions are often transient, with a vast majority of patients experiencing improvement after steroid intervention. To date, numerous cases of vaccine-induced uveitis have been reported. This study analyzed the correlation between antiviral vaccines, including the hepatitis B virus (HBV), human papillomavirus (HPV), measles-mumps-rubella (MMR), varicella zoster virus (VZV), and influenza vaccines, and different manifestations of uveitis. This is the first comprehensive study to offer a detailed analysis of uveitis types induced by antiviral vaccines. Through an extensive database search, we found a particularly strong link between influenza vaccines, followed by VZV and HPV vaccines. While anterior uveitis is common, conditions such as APMPPE, MEWDS, and VKH are particularly notable and merit careful consideration in clinical practice. Corticosteroid treatment was effective; however, half of the observed patients did not achieve full recovery, indicating potentially prolonged effects of the vaccine.

Gut microbial signatures and their functions in Behcet's uveitis and Vogt-Koyanagi-Harada disease

BACKGROUND

A number of public metagenomic studies reveal an association between the gut microbiome and various immune-mediated diseases including Behcet's uveitis (BU) and Vogt-Koyanagi-Harada disease (VKH). Integrated-analysis and subsequent validation of these results could be a potentially powerful way to understand the microbial signatures and their functions in these two uveitis entities.

METHODS

We integrated the sequencing data of our previous metagenomic studies on two major uveitis entities, BU and VKH as well as four other publicly available immune-mediated diseases datasets, including Ankylosing Spondylitis (AS), Rheumatoid Arthritis (RA), Crohn's disease (CD) and Ulcerative Colitis (UC). Alpha-diversity and beta-diversity analysis were used to compare the gut microbiome signatures between both uveitis entities and other immune-mediated diseases and healthy controls. Amino acid homology between microbial proteins and a uveitogenic peptide of the interphotoreceptor retinoid-binding protein (IRBP)161-180 was investigated using a similarity search in the NCBI protein BLAST program (BLASTP). Enzyme-linked Immunosorbent Assay (ELISA) was performed to evaluate the cross-reactive responses of experimental autoimmune uveitis (EAU)-derived lymphocytes and BU patients-derived peripheral blood mononuclear cells (PBMCs) against homologous peptides. The area under the curve (AUC) analysis was used to test the sensitivity and specificity of gut microbial biomarkers.

RESULTS

Depleted Dorea, Blautia, Coprococcus, Erysipelotrichaceae and Lachnospiraceae as well as enriched Bilophila and Stenotrophomonas were identified in BU patients. An enriched Alistipes along with a lower level of Dorea were observed in VKH patients. A peptide antigen (SteTDR) encoded by BU specifically enriched Stenotrophomonas was identified to share homology with IRBP161-180. In vitro experiments showed that lymphocytes from EAU or PBMCs from BU patients reacted to this peptide antigen as shown by the production of IFN-γ and IL-17. Addition of the SteTDR peptide to the classical IRBP immunization protocol exacerbated EAU severity. Gut microbial marker profiles consisted of 24 species and 32 species respectively differentiated BU and VKH from each other as well as from the other four immune-mediated diseases and healthy controls. Protein annotation identified 148 and 119 specific microbial proteins associated with BU and VKH, respectively. For metabolic function analysis, 108 and 178 metabolic pathways were shown to be associated with BU and VKH, respectively.

CONCLUSIONS

Our study revealed specific gut microbial signatures and their potentially functional roles in BU and VKH pathogenesis that differ significantly from other immune-mediated diseases as well as healthy controls.

LY294002 attenuates inflammatory response in endotoxin-induced uveitis by downregulating JAK3 and inactivating the PI3K/Akt signaling

CONTEXT

Uveitis is a prevalent inflammatory eye disease that damages the vision of patients and even leads to blindness. LY294002, an inhibitor of PI3K, was reported to suppress the inflammation and alleviate the progression of many diseases. However, the function of LY294002 in uveitis is unclear.

OBJECTIVE

This study aimed to explore the function of LY294002 in endotoxin-induced uveitis (EIU).

MATERIALS AND METHODS

EIU rat models were established via a single intravitreal injection of LPS. At 24 h after LPS injection, the rats received LY294002 treatment for 14 days. The histopathology was observed by H&E staining. The concentration of proinflammatory cytokines in aqueous humor was tested by ELISA. The expression of proinflammatory cytokines in the iris ciliary body (ICB) and retina of EIU rats were detected by RT-qPCR. JAK3, PI3K, and Akt expression were assessed by RT-qPCR and western blotting. Translocation of Akt in rat retinal Müller cells (rMC-1) was evaluated by immunofluorescence staining.

RESULTS

LY294002 alleviated ocular inflammation and decreased inflammatory cell infiltration in the anterior chamber, iris, ciliary body, vitreous cavity, and retina of EIU rats. LY294002 decreased the concentration of proinflammatory cytokines INF-γ, IL-17, IL-6, TNF-α, and IL-1β in aqueous humor and their expression in the ICB and retina of EIU rats. LY294002 downregulated JAK3 expression in EIU rats. LY294002 inhibited p-PI3K and p-Akt expression in EIU rats and restrained Akt translocation from cytoplasm to cell membrane in LPS-treated rMC-1 cells.

CONCLUSION

LY294002 ameliorates inflammation in EIU by downregulating JAK3 and inactivating the PI3K/Akt signaling.

Paracentral acute middle maculopathy following hepatitis B vaccine

Purpose

To report a case of paracentral acute middle maculopathy (PAMM) following Hepatitis B vaccine in a child.

Observations

A 12-year-old healthy female presented with a paracentral scotoma in the right eye due to PAMM, likely associated with a recent Hepatitis B vaccine.

Conclusions

Despite the great importance of vaccines, it is critical to promptly recognize their rare ocular complications, such as the vaccine associated PAMM described in this report.

Noninfectious Intermediate, Posterior, or Panuveitis: Results from the Retrospective, Observational, International EyeCOPE Study

Introduction

The EyeCOPE study characterized noninfectious intermediate posterior, or panuveitis (NIIPPU) before biologic agents were widely available.

Methods

This retrospective, observational study included adults with NIIPPU attending a routine ophthalmological visit. Data were collected from the study visit and medical records.

Results

Of 565 patients, 58.8% were female, and the mean age was 41.3 years; 33.8% had idiopathic uveitis and 45.8% had panuveitis. The median time from symptom onset to diagnosis and treatment was 27.0 and 30.5 days, respectively. Patients received immunosuppressants and systemic/local corticosteroids. Most patients experienced substantial decline in ocular function (mean best corrected visual acuity, 0.4 logMAR). Mean total work productivity impairment among employed patients was 31.0%. Most patients reported ocular complications (70.8%) such as vision loss and cataracts.

Conclusions

Despite treatment, most patients with NIIPPU experienced a decline in ocular function and ocular complications. There is an unmet need for additional NIIPPU treatment, such as targeted monoclonal antibodies.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40123-021-00351-4.

Anti-inflammatory effect of cortistatin in rat endotoxin-induced uveitis model

Purpose

To evaluate the anti-inflammatory effect of cortistatin (CST) in endotoxin-induced uveitis (EIU) model and to compare the results with corticosteroid treatment.

Methods

A total of 35 healthy Wistar albino rats were randomly divided into five groups. EIU was induced by a single subcutaneous injection of lipopolysaccharide (LPS). Group I received intraperitoneal (ip) normal saline (NS), Group II received ip 150 μg LPS plus NS, Group III received ip 150 μg LPS plus 250 μg/kg CST, Group IV received ip 150 μg LPS plus 1mg/kg dexamethasone, and Group V received ip 250 μg/kg CST only. The aqueous humor was collected 24 h after injection and the infiltrating cells were determined. Moreover, histopathological and immunohistochemical examinations were also performed.

Results

The clinical score and infiltrated cell count were reduced in Groups III and IV compared with Group II (P < 0.001). The pathological findings of Groups III and IV were significantly reduced compared with Group II (P < 0.001). These findings were similar between Groups III and IV (P = 1.000). Tumor necrosis factor-alpha (TNF-α) and interleukin 1 beta (IL-1β) immunoreactivity in the ciliary body of Group III and Group IV were significantly reduced compared with Group II (P < 0.001). TNF-α and IL-1β immunoreactivity in the ciliary body of Group III and Group IV were similar compared with Group I and Group V (range of P values was 0.539-0.958).

Conclusion

CST administration as a therapeutic agent might ameliorate the severity of intraocular inflammation in uveitis patients. In conclusion, effect of CST and dexamethasone in EIU model was comparable.

αB-Crystallin Alleviates Endotoxin-Induced Retinal Inflammation and Inhibits Microglial Activation and Autophagy

αB-Crystallin, a member of the small heat shock protein (sHSP) family, plays an immunomodulatory and neuroprotective role by inhibiting microglial activation in several diseases. However, its effect on endotoxin-induced uveitis (EIU) is unclear. Autophagy may be associated with microglial activation, and αB-crystallin is involved in the regulation of autophagy in some cells. The role of αB-crystallin in microglial autophagy is unknown. This study aimed to explore the role of αB-crystallin on retinal microglial autophagy, microglial activation, and neuroinflammation in both cultured BV2 cells and the EIU mouse model. Our results show that αB-crystallin reduced the release of typical proinflammatory cytokines at both the mRNA and protein level, inhibited microglial activation in morphology, and suppressed the expression of autophagy-related molecules and the number of autophagolysosomes in vitro. In the EIU mouse model, αB-crystallin treatment alleviated the release of ocular inflammatory cytokines and the representative signs of inflammation, reduced the apoptosis of ganglion cells, and rescued retinal inflammatory structural and functional damage, as evaluated by optical coherence tomographic and electroretinography. Taken together, these results indicate that αB-crystallin inhibits the activation of microglia and supresses microglial autophagy, ultimately reducing endotoxin-induced neuroinflammation. In conclusion, αB-crystallin provides a novel and promising option for affecting microglial autophagy and alleviating symptoms of ocular inflammatory diseases.

Amelioration of Endotoxin-Induced Uveitis in Rabbit by Topical Administration of Tacrolimus Proglycosome Nano-Vesicles

This work was aimed to improve the efficacy of tacrolimus in the treatment of endotoxin-induced uveitis (EIU) using propylene glycol modified lipid vesicles termed as proglycosome nano-vesicles (PNVs). PNVs were prepared by modified film hydration method. Experimental uveitis in rabbit eye was induced by an intravitreal injection of 20 μL of the endotoxin solution containing 100 ng of lipopolysaccharide endotoxin. In vivo efficacy of PNVs was determined by studying clinical symptoms of uveitis using slit lamp examination and by quantitatively measuring levels of tumor necrosis factor-alpha, interleukin-6, leukocytes and total proteins in aqueous humor, 24 h after intravitreal injection of endotoxin. Comparison was made with healthy, untreated and tacrolimus solution treated eyes. PNVs developed were nano-sized, deformable and showed sustained release of tacrolimus over period of 12 h. In vivo results indicated statistically significant difference between the effects of PNVs in the treatment of EIU compared to tacrolimus. PNV treatment not only subsides clinical symptoms of uveitis but also prevented breakdown of blood aqueous barrier. Tacrolimus loaded PNVs are potential new topical treatment for uveitis.

The Anti-Inflammatory Effects of Angiogenin in an Endotoxin Induced Uveitis in Rats

Angiogenin (ANG) is involved in the innate immune system and inflammatory disease. The aim of this study is to evaluate the anti-inflammatory effects of ANG in an endotoxin induced uveitis (EIU) rat model and the pathways involved. EIU rats were treated with balanced salt solution (BSS), a non-functional mutant ANG (mANG), or wild-type ANG (ANG). The integrity of the blood-aqueous barrier was evaluated by the infiltrating cell and protein concentrations in aqueous humor. Histopathology, Western blot, and real-time qRT-PCR of aqueous humor and ocular tissue were performed to analyze inflammatory cytokines and transcription factors. EIU treated with ANG had decreased inflammatory cells and protein concentrations in the anterior chamber. Compared to BSS and mANG, ANG treatment showed reduced expression of IL-1β, IL-8, TNF-α, and Myd88, while the expression of IL-4 and IL-10 was increased. Western blot of ANG treatment showed decreased expression of IL-6, inducible nitric oxide synthase (iNOS), IL-1β, TNF-α, and phosphorylated NF-κB and increased expression of IL-10. In conclusion, ANG seems to reduce effectively immune mediated inflammation in the EIU rat model by reducing the expression of proinflammatory cytokines, while increasing the expression of anti-inflammatory cytokines through pathways related to NF-κB. Therefore, ANG shows potential for effectively suppressing immune-inflammatory responses in vivo.

The Purinergic System as a Pharmacological Target for the Treatment of Immune-Mediated Inflammatory Diseases

Immune-mediated inflammatory diseases (IMIDs) encompass a wide range of seemingly unrelated conditions, such as multiple sclerosis, rheumatoid arthritis, psoriasis, inflammatory bowel diseases, asthma, chronic obstructive pulmonary disease, and systemic lupus erythematosus. Despite differing etiologies, these diseases share common inflammatory pathways, which lead to damage in primary target organs and frequently to a plethora of systemic effects as well. The purinergic signaling complex comprising extracellular nucleotides and nucleosides and their receptors, the P2 and P1 purinergic receptors, respectively, as well as catabolic enzymes and nucleoside transporters is a major regulatory system in the body. The purinergic signaling complex can regulate the development and course of IMIDs. Here we provide a comprehensive review on the role of purinergic signaling in controlling immunity, inflammation, and organ function in IMIDs. In addition, we discuss the possible therapeutic applications of drugs acting on purinergic pathways, which have been entering clinical development, to manage patients suffering from IMIDs.

Inhibitory role of transforming growth factor β2 in experimental autoimmune anterior uveitis

PURPOSE

Experimental autoimmune anterior uveitis (EAAU) is a clinically relevant animal model for human idiopathic anterior uveitis (IAU). The role of the immunomodulator transforming growth factor β2 (TGF-β2) in EAAU pathology is unknown. In this study, we investigated the regulatory role of TGF-β2 in EAAU.

METHODS

EAAU was induced in male Lewis rats by footpad injection of melanin-associated antigen (MAA). TGF-β2 was administered intravenously (iv) in MAA-sensitized rats during the induction of EAAU, or after the clinical onset of uveitis. MAA-sensitized rats injected similarly with an equal volume of PBS served as control. Animals were examined daily between days 7 and 30 post-injection for the clinical signs of uveitis using slit lamp biomicroscopy. Animals were sacrificed at various time points and eyes were harvested for histological analysis to assess the course and severity of inflammation. For histopathological analysis, paraffin sections of harvested eyes were stained with hematoxylin and eosin. Popliteal lymph nodes (LNs) were used for CD4⁺CD25⁺FoxP3⁺ T regulatory (Tregs) population analysis and for CD4⁺ T cell proliferation assay.

RESULTS

Administration of recombinant TGF-β2 during the early stages of EAAU prevented the induction of uveitis. Compared to PBS, the presence of TGF-β2 in the cell culture significantly (p < 0.05) inhibited the proliferation of CD4⁺ T cells in response to MAA. In MAA-sensitized Lewis rats, iv treatment with recombinant TGF-β2 resulted in significantly (p < 0.05) increased percentage of Tregs compared to animals treated similarly with PBS. Thus, TGF-β2 inhibited the induction of EAAU by inhibiting CD4⁺ T cell proliferation and increasing the number of Tregs. Injection of TGF-β2 in rats with active EAAU resulted in diminished disease activity. Unfortunately, this treatment did not lead to the early resolution of EAAU.

CONCLUSIONS

TGF-β2 plays a critical role in regulation of intraocular inflammation in EAAU. Findings reported in this study improve our understanding of immunopathology of IAU and suggest that recombinant TGF-β2 may be a promising therapeutic agent for human IAU.

Endotoxin-Induced Uveitis in Rodents

Uveitis can affect individuals of all ages, genders, and races and accounts for 10-15% of all cases of blindness. Uveitis represents a diverse array of intraocular inflammatory conditions that can be associated with complications from autoimmune diseases, bacterial infections, viral infections, chemical injuries, and metabolic issues. In rodents, endotoxin-induced uveitis (EIU) is an efficient experimental model to study pathological mechanisms associated with the disease and evaluate the pharmacological efficacy of potential new drug agents. In the EIU model, uveitis is characterized by clinically relevant inflammation, including inflammatory exudates and cells infiltrated into the anterior and vitreous eye chambers. EIU in small animal models, including rats, mice, and rabbits, is characterized by a short-lived uveal inflammation. This inflammation can be facilitated using bacterial endotoxins, such as lipopolysaccharide (LPS). In this chapter, we present a reliable, reproducible, and simplified protocol to induce EIU in mice. This method is flexible and can be applied for EIU induction in other small animals and rodents.

[Retinal transcriptome profile in mice following dexamethasone treatment for endotoxin-induced uveitis]

OBJECTIVE

To investigate the changes in retinal transcriptome profile of mice with endotoxin-induced uveitis (EIU)following dexamethasone (DEX) treatment and explore the mechanisms underlying the therapeutic effect of DEX.

METHODS

EIU was induced in BALB/c mice by intravitreal injection of 125 ng lipopolysaccharide (LPS), followed by topical applicationof DEX (0.1%) eye drops every 4 h for 24 h. The anterior chamber inflammation was examined with a slit lamp and the clinicalscores were assessed. The morphological changes in the eyes were assessed at 24 h after LPS injection. The retinas wereharvested for analysis of transcriptome profile using the next-generation sequencing (NGS)-based RNA sequencing (RNA-seq), and the expressions of the inflammatory cytokines and the differentially expressed genes (DEGs) were verified using real-timePCR.

RESULTS

DEX alleviated the inflammatory response and reduced the mRNA expressions of IL-6, TNF- a, MCP-1 andICAM-1 at 24 h after LPS injection. A total of 52 DEGs were identified by RNA-seq. Within these DEGs, 37 genes were upregulated and 15 genes were down-regulated in LPS group as compared with DEX+LPS group. No significantly enriched GeneOntology (GO) terms was noted. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis showed 6up-regulated and 2 down-regulated KEGG pathways. RIG-I-like receptor signaling pathway and several immune- andinflammation-related genes including Ifit1, H2-T24, Mx2 and Eif2ak2 were significantly down regulated by DEX. Verificationwith RT-PCR yielded results consistent with these findings.

CONCLUSIONS

DEX alleviates LPS-induced inflammatory response inthe retina of mice, and such protective effect is probably mediated by RIG-I like receptor signal pathway and the immune-andinflammation-related genes.

Amelioration of Endotoxin-Induced Inflammatory Toxic Response by a Metal Chelator in Rat Eyes

Purpose

Metal ions play a key role in exacerbating toxicity associated with oxidative stress and inflammation. This study examines the effects of a formulation containing the metal chelator ethylenediaminetetraacetic acid (EDTA) and permeability enhancer methyl sulfonyl methane (MSM) on the early course of inflammation in endotoxin-induced uveitis (EIU). The proprietary MSM/EDTA formulation of Livionex, Inc., which was used for this study, is covered by several patents and pending patent applications.

Methods

EIU was induced by using subcutaneous injection of lipopolysaccharide (LPS) into the thighs of Lewis rats. Treatment consisted of topical application to the eyes of either PBS or eye drops designated as ME that contain EDTA and MSM. Clinical signs of uveitis were monitored at 6 and 24 hours postinjection. Oxidative and inflammatory markers were evaluated by ELISA or immunohistochemistry.

Results

Rats treated with ME showed fewer clinical signs of uveitis including reduced miosis, fibrinous exudates, and dilated blood vessels. The aqueous humor of treated rats contained fewer leukocytes, lower protein levels, and less PGE₂. Formation of protein adducts with the lipid peroxidation end-product, 4-hydroxynonenal, expression of NF-κB, TNF-α, and MMP-9 were all reduced in rats treated with ME.

Conclusions

Our results indicate that ME eye drops downregulate the ocular inflammatory response in LPS treated rats, suggesting that induction of EIU involves metal ions and chelation therapy with ME is a potential treatment for uveitis.

Turning Down the Thermostat: Modulating the Endocannabinoid System in Ocular Inflammation and Pain

The endocannabinoid system (ECS) has emerged as an important regulator of both physiological and pathological processes. Notably, this endogenous system plays a key role in the modulation of pain and inflammation in a number of tissues. The components of the ECS, including endocannabinoids, their cognate enzymes and cannabinoid receptors, are localized in the eye, and evidence indicates that ECS modulation plays a role in ocular disease states. Of these diseases, ocular inflammation presents a significant medical problem, given that current clinical treatments can be ineffective or are associated with intolerable side-effects. Furthermore, a prominent comorbidity of ocular inflammation is pain, including neuropathic pain, for which therapeutic options remain limited. Recent evidence supports the use of drugs targeting the ECS for the treatment of ocular inflammation and pain in animal models; however, the potential for therapeutic use of cannabinoid drugs in the eye has not been thoroughly investigated at this time. This review will highlight evidence from experimental studies identifying components of the ocular ECS and discuss the functional role of the ECS during different ocular inflammatory disease states, including uveitis and corneal keratitis. Candidate ECS targeted therapies will be discussed, drawing on experimental results obtained from both ocular and non-ocular tissue(s), together with their potential application for the treatment of ocular inflammation and pain.

Posttranslational modification of Sirt6 activity by peroxynitrite

The mammalian sirtuin 6 (Sirt6) is a site-specific histone deacetylase that regulates chromatin structure and many fundamental biological processes. It inhibits endothelial cell senescence and inflammation, prevents development of cardiac hypertrophy and heart failure, modulates glucose metabolism, and represses tumor growth. The basic molecular mechanisms underlying regulation of Sirt6 enzymatic function are largely unknown. Here we hypothesized that Sirt6 function can be regulated via posttranslational modification, focusing on the role of peroxynitrite, one of the major reactive nitrogen species formed by excessive nitric oxide and superoxide generated during disease processes. We found that incubation of purified recombinant Sirt6 protein with 3-morpholinosydnonimine (SIN-1; a peroxynitrite donor that generates nitric oxide and superoxide simultaneously) increased Sirt6 tyrosine nitration and decreased its intrinsic catalytic activity. Similar results were observed in SIN-1-treated Sirt6, which was overexpressed in HEK293 cells, and in endogenous Sirt6 when human retinal microvascular endothelial cells were treated with SIN-1. To further investigate whether Sirt6 nitration occurs under pathological conditions, we determined Sirt6 nitration and activity in retina using a model of endotoxin-induced retinal inflammation. Our data showed that Sirt6 nitration was increased, whereas its activity was decreased, in this model. With mass spectrometry, we identified that tyrosine 257 in Sirt6 was nitrated after SIN-1 treatment. Mutation of tyrosine 257 to phenylalanine caused loss of Sirt6 activity and abolished SIN-1-induced nitration and decrease in its activity. Mass spectrometry analysis also revealed oxidation of methionine and tryptophan in Sirt6 after SIN-1 treatment. Our results demonstrate a novel regulatory mechanism controlling Sirt6 activity through reactive nitrogen species-mediated posttranslational modification under oxidative and nitrosative stress.

Inflammatory Papillitis in Uveitis: Response to Treatment and Use of Optic Nerve Optical Coherence Tomography for Monitoring

PURPOSE

To describe the clinical course of uveitis-associated inflammatory papillitis and evaluate the utility and reproducibility of optic nerve spectral domain optical coherence tomography (SD-OCT).

METHODS

Data on 22 eyes of 14 patients with uveitis-related papillitis and optic nerve imaging were reviewed. SD-OCT measure reproducibility was determined and parameters were compared in active vs. inactive uveitis.

RESULTS

Papillitis resolution lagged behind uveitis resolution in three patients. For SD-OCT measures, the intraclass correlation coefficients were 99.1-100% and 86.9-100% for intraobserver and interobserver reproducibility, respectively. All SD-OCT optic nerve measures except inferior and nasal peripapillary retinal thicknesses were significantly higher in active vs. inactive uveitis after correction for multiple hypotheses testing. Mean optic nerve central thickness decreased from 545.1 to 362.9 µm (p = 0.01).

CONCLUSIONS

Resolution of inflammatory papillitis can lag behind resolution of uveitis. SD-OCT assessment of papillitis is reproducible and correlates with presence vs. resolution of uveitis.

Oral delivery of ACE2/Ang-(1-7) bioencapsulated in plant cells protects against experimental uveitis and autoimmune uveoretinitis

Hyperactivity of the renin-angiotensin system (RAS) resulting in elevated Angiotensin II (Ang II) contributes to all stages of inflammatory responses including ocular inflammation. The discovery of angiotensin-converting enzyme 2 (ACE2) has established a protective axis of RAS involving ACE2/Ang-(1-7)/Mas that counteracts the proinflammatory and hypertrophic effects of the deleterious ACE/AngII/AT1R axis. Here we investigated the hypothesis that enhancing the systemic and local activity of the protective axis of the RAS by oral delivery of ACE2 and Ang-(1-7) bioencapsulated in plant cells would confer protection against ocular inflammation. Both ACE2 and Ang-(1-7), fused with the non-toxic cholera toxin subunit B (CTB) were expressed in plant chloroplasts. Increased levels of ACE2 and Ang-(1-7) were observed in circulation and retina after oral administration of CTB-ACE2 and Ang-(1-7) expressing plant cells. Oral feeding of mice with bioencapsulated ACE2/Ang-(1-7) significantly reduced endotoxin-induced uveitis (EIU) in mice. Treatment with bioencapsulated ACE2/Ang-(1-7) also dramatically decreased cellular infiltration, retinal vasculitis, damage and folding in experimental autoimmune uveoretinitis (EAU). Thus, enhancing the protective axis of RAS by oral delivery of ACE2/Ang-(1-7) bioencapsulated in plant cells provide an innovative, highly efficient and cost-effective therapeutic strategy for ocular inflammatory diseases.

Angiotensin-converting enzyme 2 (ACE2) activator diminazene aceturate ameliorates endotoxin-induced uveitis in mice

PURPOSE

Uveitis is a common cause of vision loss. The renin angiotensin system (RAS), which plays a vital role in cardiovascular system, is a potent mediator of inflammation and has been implicated in the pathogenesis of uveitis. A newly identified axis of RAS, ACE2/Ang-(1-7)/Mas, has emerged as a novel target because it counteracts the deleterious effect of angiotensin II. The purpose of this study was to investigate the effect of endogenous ACE2 activation in preventing endotoxin-induced uveitis (EIU) in mice.

METHODS

ACE2 activator diminazene aceturate (DIZE) was administered both systemically and locally. For systemic administration, female BALB/c mice received intraperitoneal injection of DIZE (60 mg/kg body weight [BW]) for 2 days prior to lipopolysaccharide (LPS) intravitreal injection (125 ng) to induce uveitis. For local study, DIZE was given at 0.5, 0.1, and 0 mg/mL as eyedrops six times per day for 2 days before LPS injection. The anterior segment of the mice was examined at 12, 24, 48, and 72 hours after LPS injection, and clinical scores were determined at the same time. Morphology and infiltrating inflammatory cells were evaluated after 24 hours. The mRNA levels of inflammatory cytokines were analyzed by real-time RT-PCR. ACE2 activity was determined using a self-quenching fluorescent substrate.

RESULTS

At 24 hours, the clinical score of mice treated with DIZE systemically was significantly lower (mean, ∼1.75) than the saline vehicle group (mean, ∼4) (P < 0.001). Histological examination showed 63.4% reduction of infiltrating inflammatory cells in the anterior segment and 57.4% reduction in the posterior segment of DIZE-treated eyes. The number of CD45(+) inflammatory cells in the vitreous of the DIZE-treated group was decreased (43.3%) compared to the vehicle group (P < 0.01). The mRNA levels of inflammatory cytokines were significantly reduced in the DIZE-treated group (P < 0.01, P < 0.001). The number of infiltrating inflammatory cells was also significantly reduced in eyes that received topical administration of DIZE: 73.8% reduction in the 0.5 mg/mL group and 51.7% reduction in the 0.1mg/mL group compared to the control group. DIZE treatment resulted in significantly increased ACE2 activity in the retina (P < 0.001).

CONCLUSIONS

Endogenous ACE2 activation by DIZE has a preventive effect on LPS-induced ocular inflammation in the EIU mouse model. These results support the notions that RAS plays a role in modulating ocular immune response and that enhancing ACE2 provides a novel therapeutic strategy for uveitis.

Plasma metabonomics study of the patients with acute anterior uveitis based on ultra-performance liquid chromatography-mass spectrometry

BACKGROUND

The identification of the biomarkers of patients with acute anterior uveitis (AAU) may allow for a less invasive and more accurate diagnosis, as well as serving as a predictor in AAU progression and treatment response. The aim of this study was to identify the potential biomarkers and the metabolic pathways from plasma in patients with AAU.

METHODS

Both plasma metabolic biomarkers and metabolic pathways in the AAU patients versus healthy volunteers were investigated using ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) and a metabonomics approach. The principal component analysis (PCA) was used to separate AAU patients from healthy volunteers as well as to identify the different biomarkers between the two groups. Metabolic compounds were matched to the KEGG, METLIN, and HMDB databases, and metabolic pathways associated with AAU were identified.

RESULTS

The PCA for UPLC-MS data shows that the metabolites in AAU patients were significantly different from those of healthy volunteers. Of the 4,396 total features detected by UPLC-MS, 102 features were significantly different between AAU patients and healthy volunteers according to the variable importance plot (VIP) values (greater than two) of partial least squares discriminate analysis (PLS-DA). Thirty-three metabolic compounds were identified and were considered as potential biomarkers. Meanwhile, ten metabolic pathways were found that were related to the AAU according to the identified biomarkers.

CONCLUSIONS

These data suggest that metabolomics study can identify potential metabolites that differ between AAU patients and healthy volunteers. Based on the PCA, PLS-DA, several potential metabolic biomarkers and pathways in AAU patients were found and identified. In addition, the UPLC-MS technique combined with metabonomics could be a suitable systematic biology tool in research in clinical problems in ophthalmology, and can provide further insight into the pathophysiology of AAU.

Ocular inflammation in uveal tract in aged obese type 2 diabetic rats (Spontaneously Diabetic Torii fatty rats)

We report uveitis observed in an obese type 2 diabetes rat model, Spontaneously Diabetic Torii Lepr(fa) (SDT fatty) rats aged over 50 weeks. The eyes of SDT fatty rats (16 animals: 7 males and 9 females with 50 or 60 weeks of age) were examined histopathologically. Infiltration of inflammatory cells in the uveal tract was observed in 13 of 16 animals. One female showed severe inflammation affecting the entire uveal tract including the iris, ciliary body, and choroid with a variety of inflammatory cells (neutrophils, lymphocytes, and macrophages). Those changes clinically mimic the findings of diabetic iridocyclitis in diabetic patients. Uveitis associated with diabetes can occur in diabetic patients but the pathogenesis still remains unknown. Since increased extramedullary hematopoiesis in the spleen and abscess in the genital and lower urinary tracts were observed in some SDT fatty rats, increased susceptibility to infection, prolongation of inflammatory states, and disorders of the immune system were considered to be possible factors of the uveitis in aged SDT fatty rats. There have been few reports on how diabetes has influence on the development of uveitis associated with bacterial infection. The SDT fatty rat can be an animal model to investigate diabetes-associated uveitis.

Antioxidants and vision health: facts and fiction

A number of nutritional supplements containing antioxidants are advertised for better vision health. Do they benefit the average consumer? The literature was examined for the effectiveness of antioxidants for human eye health, and for the intricacies in collection of such evidence. The following diseases were considered: cataract, glaucoma, age-related macular degeneration (AMD), retinopathy, retinitis pigmentosa, eye infections, and uveitis. The literature indicates that antioxidant supplements plus lutein have a reasonable probability of retarding AMD. For glaucoma, such supplements were ineffectual in some studies but useful in others. In some studies, antioxidant rich fruits and vegetables were also useful for protection against glaucoma. For diabetic retinopathy, antioxidant supplements may have a small benefit, if any, but only as an adjunct to glycemic control. In very high-risk premature retinopathy and retinitis pigmentosa, antioxidant supplements may be beneficial but those with excess Vitamin E should be avoided. For cataract, there is no evidence for an advantage of such nutritional supplements. However, lubricant drops containing N-acetylcarnosine may be helpful in initial stages of the disease. For eye infections and other causes of uveitis, antioxidants have not been found useful. We recommend that a diet high in antioxidant rich foods should be developed as a habit from an early age. However, when initial signs of vision health deterioration are observed, the appropriate nutritional supplement products may be recommended but only to augment the primary medical treatments.

The future of uveitis treatment

Uveitis is a heterogeneous collection of diseases with polygenic and environmental influences. This heterogeneity presents challenges in trial design and selection of end points. Despite the multitude of causes, therapeutics targeting common inflammatory pathways are effective in treating diverse forms of uveitis. These treatments, including corticosteroids and immunomodulatory agents, although often effective, can have untoward side effects, limiting their utility. The search for drugs with equal or improved efficacy that are safe is therefore paramount. A mechanism-based approach is most likely to yield the future breakthroughs in the treatment of uveitis. We review the literature and provide examples of the nuances of immune regulation and dysregulation that can be targeted for therapeutic benefit. As our understanding of the causes of uveitis grows we will learn how to better apply antibodies designed to block interaction between inflammatory cytokines and their receptors. T-lymphocyte activation can be targeted by blocking co-stimulatory pathways or inhibiting major histocompatibility complex protein interactions. Furthermore, intracellular downstream molecules from cytokine or other pathways can be inhibited using small molecule inhibitors, which have the benefit of being orally bioavailable. An emerging field is the lipid-mediated inflammatory and regulatory pathways. Alternatively, anti-inflammatory cytokines can be provided by administering recombinant protein, and intracellular "brakes" of inflammatory pathways can be introduced potentially by gene therapy. Novel approaches of delivering a therapeutic substance include, but are not limited to, the use of small interfering RNA, viral and nonviral gene therapy, and microparticle or viscous gel sustained-release drug-delivery platforms.

Anterior uveitis and cataract after rubella vaccination: a case report of a 12-month-old girl

Many reports associating uveitis after vaccination have been reported, including 2 cases after measles, mumps, and rubella (MMR) vaccine. We report the case of a 12-month-old girl who developed a unilateral anterior uveitis with rubeosis and cataract 3 months after an MMR vaccination at 9 months of age. Aqueous humor analysis showed the presence of more rubella-specific immunoglobulin G in the affected eye than in the unaffected one. This is the second report showing an association between MMR vaccine and anterior uveitis and the first supported by the presence of intraocular rubella antibodies.

Topical tacrolimus nanoemulsion, a promising therapeutic approach for uveitis

Uveitis is a sight threatening inflammatory disorder that affects all ages and remains a significant cause of visual loss. Inflammatory activity plays an important role in the whole pathogenesis of uveitis. Treatment of uveitis is mainly driven by corticosteroids that have potential side effects. Recent investigations demonstrated that tacrolimus inhibits T-cell proliferation and suppresses release of inflammatory cytokines. Since tacrolimus is a definite immunosuppressive agent, and since inflammatory process has been involved in uveitis, the compound must have effect on the progression of uveitis through reduction in inflammatory activity. Even results of the clinical trials demonstrate that tacrolimus have useful role in treatment of sight threatening uveitis that is refractory to other therapy. Studies also indicate that long term use of tacrolimus is well tolerated. However, its use in uveitis is limited because of its poor physico-chemical properties including poor aqueous solubility and high molecular weight (822 Da). Therefore, we have proposed that tacrolimus nanoemulsion administered topically is a promising therapeutic approach to treat uveitis. Based on previous evidences, we have hypothesized that nanoemulsion formulation of tacrolimus can improve efficacy and safety profile of tacrolimus.

Endotoxin-induced uveitis in rodents

Uveitis is a common cause of vision loss, accounting for 10-15 % of all cases of blindness worldwide and affects individuals of all ages, genders, and races. Uveitis represents a broad range of intraocular inflammatory conditions due to complications of autoimmune diseases, bacterial infections, viral infections, and chemical and metabolic injuries. Endotoxin-induced uveitis (EIU) in rodents is an efficient experimental model to investigate the pathological mechanism and pharmacological efficacy of potential drug agents. EIU is characterized by clinically relevant classical signs of inflammation, including inflammatory exudates and cells in the anterior and vitreous chambers. EIU in small animal models such as rats, mice, and rabbits is a short-lived uveal inflammation that can be developed subsequent to administration of bacterial endotoxin, such as lipopolysaccharide. Here, we present a reproducible, reliable, and simplified protocol to induce EIU in mice. This method could be used with similar efficacy for EIU induction in other small animals as well.

Aldose reductase deficiency protects from autoimmune- and endotoxin-induced uveitis in mice

PURPOSE

To investigate the effect of aldose reductase (AR) deficiency in protecting the chronic experimental autoimmune (EAU) and acute endotoxin-induced uveitis (EIU) in c57BL/6 mice.

METHODS

The WT and AR-null (ARKO) mice were immunized with human interphotoreceptor retinoid-binding peptide (hIRPB-1-20), to induce EAU, or were injected subcutaneously with lipopolysaccharide (LPS; 100 μg) to induce EIU. The mice were killed on day 21 for EAU and at 24 hours for EIU, when the disease was at its peak, and the eyes were immediately enucleated for histologic and biochemical studies. Spleen-derived T-lymphocytes were used to study the antigen-specific immune response in vitro and in vivo.

RESULTS

In WT-EAU mice, severe damage to the retinal wall, especially to the photoreceptor layer was observed, corresponding to a pathologic score of ∼2, which was significantly prevented in the ARKO or AR inhibitor-treated mice. The levels of cytokines and chemokines increased markedly in the whole-eye homogenates of WT-EAU mice, but not in ARKO-EAU mice. Further, expression of inflammatory marker proteins such as inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2, tumor necrosis factor (TNF)-α, and vascular cell adhesion molecule (VCAM)-1 was increased in the WT-EIU mouse eyes but not in the ARKO-EIU eyes. The T cells proliferated vigorously when exposed to the hIRPB antigen in vitro and secreted various cytokines and chemokines, which were significantly inhibited in the T cells isolated from the ARKO mice.

CONCLUSIONS

These findings suggest that AR-deficiency/inhibition protects against acute as well as chronic forms of ocular inflammatory complications such as uveitis.

Preventive effects of ethyl pyruvate on endotoxin-induced uveitis in rats

PURPOSE

Recent studies indicate that ethyl pyruvate (EP) exerts anti-inflammatory properties; however, the effect of EP on ocular inflammation is not known. The efficacy of EP in endotoxin-induced uveitis (EIU) in rats was investigated.

METHODS

EIU in Lewis rats was developed by the subcutaneous injection of lipopolysaccharide (LPS; 150 μg). EP (30 mg/kg body weight) or its carrier was injected intraperitoneally 1 hour before or 2 hours after lipopolysaccharide injection. Animals were killed after 3 and 24 hours followed by enucleation of eyes and collection of the aqueous humor (AqH). The number of infiltrating cells and levels of proteins in the AqH were determined. The rat cytokine/chemokine multiplex method was used to determine level of cytokines and chemokines in the AqH. TNF-α and phospho-nuclear factor kappa B (NF-κB) expression in ocular tissues were determined immunohistochemically. Human primary nonpigmented ciliary epithelial cells (HNPECs) were used to determine the in vitro efficacy of EP on lipopolysaccharide-induced inflammatory response.

RESULTS

Compared to controls, AqH from the EIU rat eyes had a significantly higher number of infiltrating cells, total protein, and inflammatory cytokines/chemokines, and the treatment of EP prevented EIU-induced increases. In addition, EP also prevented the expression of TNF-α and activation of NF-κB in the ciliary bodies and retina of the eye. Moreover, in HNPECs, EP inhibited lipopolysaccharide-induced activation of NF-κB and expression of Cox-2, inducible nitric oxide synthase, and TNF-α.

CONCLUSIONS

Our results indicate that EP prevents ocular inflammation in EIU, suggesting that the supplementation of EP could be a novel approach for the treatment of ocular inflammation, specifically uveitis.

Emerging role of antioxidants in the protection of uveitis complications

Current understanding of the role of oxidative stress in ocular inflammatory diseases indicates that antioxidant therapy may be important to optimize the treatment. Recently investigated antioxidant therapies for ocular inflammatory diseases include various vitamins, plant products and reactive oxygen species scavengers. Oxidative stress plays a causative role in both non-infectious and infectious uveitis complications, and novel strategies to diminish tissue damage and dysfunction with antioxidant therapy may ameliorate visual complications. Preclinical studies with experimental animals and cultured cells demonstrate significant anti-inflammatory effects of a number of promising antioxidant agents. Many of these antioxidants are under clinical trial for various inflammatory diseases other than uveitis such as cardiovascular, rheumatoid arthritis and cancer. Well planned interventional clinical studies in the field of ocular inflammation will be necessary to sufficiently investigate the potential medical benefits of antioxidant therapies for uveitis. This review summarizes the recent investigations of novel antioxidant agents for ocular inflammation, with selected studies focused on uveitis.

Hepatitis B vaccine and uveitis: an emerging hypothesis suggested by review of 32 case reports

OBJECTIVE

To report a possible association between hepatitis B vaccine and uveitis.

METHODS

Spontaneous reports from the National Registry of Drug-Induced Ocular Side Effects, the World Health Organization, and the Food and Drug Administration were collected on hepatitis B vaccine associated with uveitis between 1982 and 2009. In addition, we performed a Medline literature search using the keywords of uveitis, iritis, or vitritis, in combination with vaccines and hepatitis B vaccine. Data garnered from the spontaneous reports included age, gender, adverse drug reaction, temporal association of uveitis with vaccine doses, concomitant drugs, other systemic disease, recovery, and recurrence after repeat dosage.

RESULTS

Thirty-two case reports of uveitis occurring after hepatitis B vaccine were reported to the spontaneous reporting databases. The mean age of the patients was 29 years (1-57 years), with 8 male and 24 female patients. The mean number of days until uveitis was reported after vaccination was 3 days (1-15 days). The uveitis was reported to occur after the first vaccination in 15 patients, after the second vaccination in 3 patients, and after the third vaccination in 3 patients; the duration of time to occurrence of uveitis was not reported for 9 patients. One patient had recurrent uveitis after both the second and third doses of vaccine. One patient had recurrent uveitis after the first and second doses of vaccine.

CONCLUSION

Hepatitis B vaccine may have a possible association with the development of uveitis in some patients. Immune complex deposition and adjuvant effects are potential pathogenic mechanisms.

Prevention of endotoxin-induced uveitis in rats by plant sterol guggulsterone

PURPOSE

To investigate the anti-inflammatory effects of guggulsterone, an antioxidant and antitumor agent, in endotoxin-induced uveitis (EIU) in rats and to elucidate the underlying molecular mechanism or mechanisms related to ocular inflammation.

METHODS

EIU was induced by subcutaneous injection of lipopolysaccharide (LPS; 150 μg) into Lewis rats treated with guggulsterone (30 mg/kg body weight, intraperitoneally) or its carrier. After 24 hours the rats were killed, eyes were enucleated, and aqueous humor (AqH) was collected. Numbers of infiltrating cells and levels of matrix metalloproteinase-2 (MMP-2), nitric oxide (NO), and prostaglandin E(2) (PGE(2)) were determined in AqH by specific ELISAs. An antibody array was used to measure the expression of various inflammatory cytokines in AqH. The expression of MMP-2, iNOS, Cox-2, phospho-IκB, and phospho-NF-κB was determined immunohistochemically. Human primary nonpigment ciliary epithelial cells (HNPECs) were used to determine the in vitro efficacy of guggulsterone on the LPS-induced inflammatory response.

RESULTS

Compared with control, the EIU rat eye AqH had a significantly higher number of infiltrating cells, total protein, and inflammatory markers, such as MMP-2, NO, and PGE(2), and the treatment of guggulsterone prevented EIU-induced increases. Guggulsterone also prevented the expression of MMP-2, iNOS, and Cox-2 proteins and of IκB and NF-κB in various eye tissues. Moreover, in cultured HNPECs, guggulsterone inhibited LPS-induced expression of inflammatory proteins.

CONCLUSIONS

These results for the first time demonstrate that the plant sterol guggulsterone suppresses ocular inflammation in EIU, suggesting that the supplementation of guggulsterone could be a novel approach for the treatment of ocular inflammation.

Tumor necrosis factor-alpha converting enzyme: Implications for ocular inflammatory diseases

Tumor necrosis factor-alpha (TNF-alpha) converting enzyme (TACE), a member of the family of metalloproteinase disintegrin proteins, is responsible for the conversion of inactive TNF-alpha precursor form to active mature form. TNF-alpha is a pleiotropic cytokine that contributes to cellular immunity and inflammatory response in wide range of inflammatory pathologies. Although a large number of studies indicate the use of TACE inhibitors, which prevents processing of TNF-alpha as potential therapeutic drugs for the treatment of inflammatory diseases including rheumatoid arthritis, Crohn's disease and cancer, very few studies indicate its use in ocular pathologies. It is still not clearly understood how the TACE-mediated shedding of cytokines and growth factors in various ocular tissues plays a critical role in the cytotoxic signals causing tissue dysfunction and damage leading to blindness. Regulation of TACE activity is likely to have wide implications for ocular immunology and inflammatory diseases. Specifically, since anti-TNF-alpha therapies have been used to prevent ocular inflammatory complications, the use of TACE inhibitors could be a novel therapeutic approach for ocular inflammatory diseases especially uveitis.

Arginase activity mediates retinal inflammation in endotoxin-induced uveitis

Arginase has been reported to reduce nitric oxide bioavailability in cardiovascular disease. However, its specific role in retinopathy has not been studied. In this study, we assessed the role of arginase in a mouse model of endotoxin-induced uveitis induced by lipopolysaccharide (LPS) treatment. Measurement of arginase expression and activity in the retina revealed a significant increase in arginase activity that was associated with increases in both mRNA and protein levels of arginase (Arg)1 but not Arg2. Immunofluorescence and flow cytometry confirmed this increase in Arg1, which was localized to glia and microglia. Arg1 expression and activity were also increased in cultured Muller cells and microglia treated with LPS. To test whether arginase has a role in the development of retinal inflammation, experiments were performed in mice deficient in one copy of the Arg1 gene and both copies of the Arg2 gene or in mice treated with a selective arginase inhibitor. These studies showed that LPS-induced increases in inflammatory protein production, leukostasis, retinal damage, signs of anterior uveitis, and uncoupling of nitric oxide synthase were blocked by either knockdown or inhibition of arginase. Furthermore, the LPS-induced increase in Arg1 expression was abrogated by blocking NADPH oxidase. In conclusion, these studies suggest that LPS-induced retinal inflammation in endotoxin-induced uveitis is mediated by NADPH oxidase-dependent increases in arginase activity.

Retinal vasculitis associated with asymptomatic Gardnerella vaginalis infection: a new clinical entity

PURPOSE

To report on 3 cases of retinal vasculitis associated with asymptomatic Gardnerella vaginalis (GV) infection.

METHODS

Review of 3 consecutive patients who presented with central retinal vasculitis without signs or symptoms of systemic disease. The vasculitis involved the central branches of the retinal vessels bilaterally and was steroid-dependent.

RESULTS

During treatment, patients developed clinically significant vaginitis, which the gynecologist considered to be exacerbated by the steroid treatment, leading to its withdrawal. All 3 vaginal specimens were positive for GV. Antibiotic susceptibility testing led to administration of oral ampicillin (2 g/day for 10 days), which resolved both the vaginal infection and the retinal vasculitis.

CONCLUSIONS

Idiopathic retinal vasculitis can be triggered by several agents. In this case series, GV was associated with retinal vasculitis, which was resolved by oral ampicillin. GV infection may be one of a number of triggers of retinal vasculitis. Appropriate treatment and full resolution of ocular inflammation requires exclusion of possible underlying infections.

Extraintestinal manifestations of inflammatory bowel disease

Inflammatory bowel disease (IBD) is associated with a variety of extraintestinal manifestations (EIMs) that may produce greater morbidity than the underlying intestinal disease and may even be the initial presenting symptoms of the IBD. As many as 36% of patients with IBD have at least one EIM. Some are more common related to active colitis (joint, skin, ocular, and oral manifestations). Others are especially seen with small bowel dysfunction (cholelithiasis, nephrolithiasis, and obstructive uropathy), and some are nonspecific disorders (osteoporosis, hepatobiliary disease, and amyloidosis). Patients with perianal Crohn's disease are at higher risk for developing EIMs than other IBD patients. Also the presence of one EIM appears to confer a higher likelihood of developing other manifestations than would be expected by chance alone. The identified pathogenetic autoimmune mechanisms include genetic susceptibility antigenic display of autoantigen, aberrant self-recognition, and immunopathogenetic autoantibodies against organ-specific cellular antigen(s) shared by colon and extra-colonic organs. Microbes may play an important role, probably by molecular mimicry. Early recognition of these extraintestinal manifestations should help guide therapy that will reduce overall morbidity in affected patients. This paper reviews the diagnosis, therapy and management of the more common EIMs.

Eye-concentrated distribution of dexamethasone carried by sugar-chain modified liposome in experimental autoimmune uveoretinitis mice

Corticosteroid is generally accepted as a standard therapeutic agent for active inflammatory (and) autoimmune eye diseases. In an attempt to develop a system to deliver corticosteroid most efficiently to the target eye, a sialyl-Lewis X (sLe(x))-conjugated liposome was adopted as a candidate for a carrier of dexamethasone (Dexa) and tissue distribution of intravenous Dexa with the modified liposome as well as Dexa alone as control was studied in normal and experimental autoimmune uveoretinitis (EAU) mice. Intravenous Dexa (1 mg) was widely distributed in all the tissues (eye, brain, heart, lung, liver, kidney, spleen and intestine) examined in similar manner in both mice and Dexa concentration was lowest in the eye except the brain. The tissue concentrations of Dexa in EAU group were all significantly lower than those in the corresponding tissues in normal group. Intravenous Dexa (2 microg) in the modified liposome was almost concentrated to the eye in EAU mice, reaching 13.84 ng/mg tissue in contrast to 2.34 ng/mg tissue in Dexa (1 mg) alone administered EAU mice. In normal mice, Dexa was undetectable in any tissues examined and thus the effect of the modified liposome was not observed. The result supported the potentiality of sLe(x)-conjugated liposome for target-delivering of corticosteroid to inflamed eye.

Aldose reductase inhibition prevents endotoxin-induced uveitis in rats

PURPOSE

The purpose of the present study was to elucidate the role of the polyol pathway enzyme aldose reductase (AR) in the mediation of ocular inflammation in a rat model of endotoxin-induced uveitis (EIU).

METHODS

EIU was induced by a subcutaneous injection of 200 microg lipopolysaccharide (LPS) in male Lewis rats treated with the AR inhibitor, zopolrestat (25 mg/kg body weight, intraperitoneally) or its carrier. The rats were killed 24 hours after LPS injection, the eyes were enucleated immediately, and aqueous humor (AqH) was collected. The number of infiltrating cells, protein concentration, and levels of nitric oxide (NO), tumor necrosis factor (TNF)-alpha, and prostaglandin E(2) (PGE(2)) in the AqH were determined. Immunohistochemical analysis was performed in paraformaldehyde-fixed eye sections by staining with antibodies against iNOS, COX-2, TNF-alpha, NF-kappaB, and AR. The levels of reactive oxygen species (ROS) in rat eye sections were determined by dihydroethidium (hydroethidine) fluorescence staining.

RESULTS

In the EIU rat eye AqH, both the number of infiltrating cells and protein concentrations of the inflammatory markers, TNF-alpha, NO, and PGE(2) were significantly higher than in the control rats, and inhibition of AR by zopolrestat suppressed the LPS-induced increases. The LPS-induced increased expression of AR, TNF-alpha, iNOS, and COX-2 proteins in the ciliary body, corneal epithelium, and retinal wall was also significantly inhibited by zopolrestat. Furthermore, AR inhibition prevented the LPS-induced increased levels of ROS and activation of NF-kappaB in the ciliary body, corneal epithelium, and retinal wall of the rat eye. AR inhibition also prevented the LPS-induced activation of NF-kappaB and expression of COX-2 and iNOS in the human monocyte cell line U-937.

CONCLUSIONS

The results indicate that AR inhibition suppresses the inflammation in EIU by blocking the expression and release of inflammatory markers in ocular tissues, along with the attenuation of NF-kappaB activation. This finding suggests that AR inhibition could be a novel therapeutic target for the treatment of uveitis and associated ocular inflammation.

Infliximab Therapy in Children and Adolescents with Inflammatory Bowel Disease

This review summarises the present knowledge of infliximab therapy in children with inflammatory bowel disease (IBD) based on the available published literature. Infliximab, the chimeric monoclonal IgG(1) antibody to tumour necrosis factor-alpha, is indicated for medically refractory luminal and fistulising paediatric Crohn's disease. Recently, ulcerative colitis case series in children and adolescents suggested that infliximab might also be effective for treatment of ulcerative colitis resistant to standard medical therapy. Induction therapy with infliximab 5 mg/kg at weeks 0, 2 and 6 is routinely used. Since the majority of patients will relapse if not re-treated, a long-term approach with systematic re-treatment with 5 mg/kg every 8-12 weeks is recommended. Maintenance therapy every 8 weeks was superior to 12 weeks' administration in maintaining response and remission in the largest-to-date paediatric randomised trial. Concomitant immunosuppressive therapy reduces the risk of infliximab antibody formation and infusion reactions, and prolongs the duration of treatment success. Severe reactions may not be an absolute contraindication to future infliximab therapy. Premedication does not prevent the development of infusion reactions; however, it is indicated for prevention of subsequent infusion reactions. Adverse events and safety findings in children are comparable to those observed in adults. Latent tuberculosis needs to be screened for. Malignancy rates in paediatric patients treated with infliximab do not seem to be increased. However, newly reported cases of hepatosplenic T-cell lymphoma in young patients with IBD treated with infliximab and mercaptopurine therapy raise concern, and long-term follow-up studies are necessary to determine the true malignancy risk.