Fluocinolone Inhibits VEGF Expression via Glucocorticoid Receptor in Human Retinal Pigment Epithelial (ARPE-19) Cells and TNF-α–Induced Angiogenesis in Chick Chorioallantoic Membrane (CAM)

Ocular, Visual, and Anatomical Outcomes in Eyes Requiring Incisional Intraocular Pressure-Lowering Surgery Following the 0.19-mg Fluocinolone Acetonide Intravitreal Implant

BACKGROUND AND OBJECTIVE

To assess ocular, visual, and anatomical outcomes following the 0.19-mg fluocinolone acetonide (FAc) intravitreal implant (ILUVIEN®) and incisional intraocular pressure (IOP)-lowering surgery in diabetic macular edema.

PATIENTS AND METHODS

From a 36-month, phase 4, open-label, observational study (N = 202 eyes, 159 patients), 8 eyes (7 patients) required IOP-lowering surgery post-FAc; eyes were segregated by FAc-induced (n = 5, 2.47%) versus neovascular glaucoma (NVG)-related (n = 3, 1.49%) IOP elevations and assessed for IOP, best corrected visual acuity (BCVA), central subfield thickness (CST), and cup-to-disc ratio (c/d).

RESULTS

Changes at 36 months were +5.4 letters BCVA (P > 0.05) and +0.09 c/d (P = 0.0217); IOP and CST were unchanged. FAc-induced-group eyes required fewer IOP-lowering medications than NVG-group eyes (2.0 versus 4.0; P < 0.01) but for longer duration (15.2 versus 2.6 months; P < 0.001).

CONCLUSIONS

Post-FAc IOP-lowering surgery, regardless of cause, largely did not affect the outcomes measured; these procedures, then, may not meaningfully threaten positive outcomes. [Ophthalmic Surg Lasers Imaging Retina 2024;55:22-29.].

Diabetic retinopathy: emerging concepts of current and potential therapy

Diabetic retinopathy (DR) is one of the leading causes of permanent central blindness worldwide. Despite the complexity and inadequate understanding of DR pathogenesis, many of the underlying pathways are currently partially understood and may offer potential targets for future treatments. Anti-VEGF medications are currently the main medication for this problem. This article provides an overview of the established pharmacological treatments and those that are being developed to cure DR. We firstly reviewed the widely utilized approaches including pan-retinal photocoagulation therapy, anti-VEGF therapy, corticosteroid therapy, and surgical management of DR. Next, we discussed the mechanisms of action and prospective benefits of novel candidate medications. Current management are far from being a perfect treatment for DR, despite mild-term favorable efficiency and safety profiles. Pharmacological research should work toward developing longer-lasting treatments or new drug delivery systems, as well as on identifying new molecular targets in the pathogenetical mechanism for DR. In order to find a treatment that is specifically designed for each patient, it is also necessary to properly characterize patients, taking into account elements like hereditary factors and intraretinal neovascularization stages for effective utilization of drugs. The current and potential approaches for diabetic retinopathy. Image was constructed using Biorender.com.

Microneedles for advanced ocular drug delivery

In the field of ocular drug delivery, topical delivery remains the most common treatment option for managing anterior segment diseases, whileintraocular injectionsare the current gold standard treatment option for treating posterior segment diseases. Nonetheless, topical eye drops are associated with low bioavailability (<5%), and theintravitreal administration procedure is highly invasive, yielding poor patient acceptability. In both cases, frequent administration is currently required. As a result, there is a clear unmet need for sustained drug delivery to the eye, particularly in a manner that can be localised. Microneedles, which are patches containing an array of micron-scale needles (<1 mm), have the potential to meet this need. These platforms can enable localised drug delivery to the eye while enhancing penetration of drug molecules through key ocular barriers, thereby improving overall therapeutic outcomes. Moreover, the minimally invasive manner in which microneedles are applied could provide significant advantages over traditional intravitreal injections regarding patient acceptability. Considering the benefitsofthis novel ocular delivery system, this review provides an in-depth overviewofthe microneedle systems for ocular drug delivery, including the types of microneedles used and therapeutics delivered. Notably, we outline and discuss the current challenges associated with the clinical translation of these platforms and offer opinions on factors which should be considered to improve such transition from lab to clinic.

Intravitreal Fluocinolone Acetonide Implant (ILUVIEN®) for the Treatment of Retinal Conditions. A Review of Clinical Studies

Fluocinolone acetonide (FAc) intravitreal implant (Iluvien®) is a corticosteroid implant indicated for the treatment of diabetic macular oedema (DMO) in patients who have previously received conventional treatment without good response, non-infectious posterior uveitis, and as an off-label treatment of the macular oedema secondary to retinal vein occlusion. FAc is a non-biodegradable 0.19 mg intravitreal implant which is designed to release FAc over 3 years at a rate of approximately 0.2 mcg per day. The aim of this review is to describe the special pharmacological properties of Iluvien and display the outcomes of the most important clinical trials and real-world studies regarding its efficacy and safety for the management of the above retinal disorders.

Intravitreal Fluocinolone Acetonide for Diabetic Macular Edema: Long-Term Effect and Structure/Function Correlation

The long-term effect of intravitreal Fluocinolone acetonide (FAc) on retinal morphology and function in diabetic macular edema (DME) was investigated. Seventeen eyes of twelve consecutive DME patients, treated by intravitreal FAc, were retrospectively evaluated. Retinal morphology was assessed with central macular thickness (CMT). Retinal function was assessed by best-corrected visual acuity (BCVA) and cone b-wave and photopic negative response (PhNR). The main outcome was a mean change in CMT at month 24. The secondary outcomes were changes in cone b-wave and PhNR at month 24. The incidence of adverse events was also recorded. Mean CMT decreased from 406.52 µm (±138.74) at baseline to 310 µm (±130.39) at 24 months (p = 0.008). No significant changes in the other parameters were found. At baseline, BCVA and PhNR amplitude were negatively correlated (r = −0.55) with CMT. At the end of follow-up, the change in CMT was negatively correlated with baseline CMT (r = −0.53, p = 0.03) and positively correlated with baseline PhNR amplitude (r = 0.58, p < 0.01). A significant, long-term reduction in CMT was observed in DME patients after FAc implant. The anti-edema effect tended to be stronger in patients with the poorest baseline retinal morphology (CMT) and function (PhNR). Structure/function correlations might help to characterize the patients who may benefit from this treatment.

Dexamethasone: Insights into Pharmacological Aspects, Therapeutic Mechanisms, and Delivery Systems

Dexamethasone (DEX) has been widely used to treat a variety of diseases, including autoimmune diseases, allergies, ocular disorders, cancer, and, more recently, COVID-19. However, DEX usage is often restricted in the clinic due to its poor water solubility. When administered through a systemic route, it can elicit severe side effects, such as hypertension, peptic ulcers, hyperglycemia, and hydro-electrolytic disorders. There is currently much interest in developing efficient DEX-loaded nanoformulations that ameliorate adverse disease effects inhibiting advancements in scientific research. Various nanoparticles have been developed to selectively deliver drugs without destroying healthy cells or organs in recent years. In the present review, we have summarized some of the most attractive applications of DEX-loaded delivery systems, including liposomes, polymers, hydrogels, nanofibers, silica, calcium phosphate, and hydroxyapatite. This review provides our readers with a broad spectrum of nanomedicine approaches to deliver DEX safely.

Comparison of the intraocular pressure following an intravitreal triamcinolone acetonide injection for diabetic macula oedema in vitrectomised and non-vitrectomised eyes

Purpose

To compare the intraocular pressure (IOP) after an intravitreal triamcinolone acetonide (IVTA) between vitrectomised and non-vitrectomised eyes in patients with diabetes and diabetic macular oedema (DME).

Design

Retrospective comparative study

Methods

Medical records of 157 patients (157 eyes) with type 2 diabetes who received IVTA for DME were reviewed, and the best-corrected visual acuity, IOP and optical central retinal thickness (CRT) were compared preoperatively, at 1, 4, 12 and 24 weeks after IVTA between the vitrectomised and non-vitrectomised groups.

Results

IOP significantly increased at 1 (p<0.0001), 4 (p<0.0001), 8 (p<0.0001), 12 (p=0.0019), 16 (p=0.0006) and 20 weeks (p=0.0191) in the non-vitrectomised group, whereas a significant increase was only observed at 1 (p=0.0003) and 4 weeks (p=0.0006) in the vitrectomised group. ΔIOP, IOP changes from baseline, in the non-vitrectomised group was significantly higher than that in the vitrectomised group at 4 (p=0.0014), 8 (p=0.0081), 12 (p=0.0032) and 16 weeks (p=0.0038). No significant difference was observed in logMAR and CRT at any time point after IVTA between the two groups.

Conclusions

After an initial IVTA, increased IOP and ΔIOP from the baseline IOP were significantly more frequently observed in the non-vitrectomised than that in the vitrectomised group. IVTA is a safer and more effective treatment option for DME in vitrectomised than that in non-vitrectomised eyes.

Corticosteroids in ophthalmology: drug delivery innovations, pharmacology, clinical applications, and future perspectives

Corticosteroids remain the mainstay of the treatment for various ocular conditions affecting the ocular surface, anterior and posterior segments of the eye due to their anti-inflammatory, anti-oedematous, and anti-neovascularization properties. Prednisolone, prednisolone acetate, dexamethasone, triamcinolone acetonide, fluocinolone acetonide, and loteprednol etabonate are amongst the most widely used ophthalmic corticosteroids. Corticosteroids differ in their activity and potency in the eye due to their inherent pharmacological and pharmaceutical differences. Different routes and regimens are available for ocular administration of corticosteroids. Conventional topical application to the eye is the route of choice when targeting diseases affecting the ocular surface and anterior segment, while periocular, intravitreal, and suprachoroidal injections can be potentially effective for posterior segment diseases. Corticosteroid-induced intraocular pressure elevation and cataract formation remain the most significant local risks following topical as well as systemic corticosteroid administration. Invasive drug administration via intracameral, subconjunctival, and intravitreal injection can enhance ocular bioavailability and minimize dose and dosing frequency of administration, yet may exacerbate ocular side effects of corticosteroids. This review provides a critical appraisal of the ophthalmic uses of corticosteroid, routes of administration, drug delivery fundamentals and novel ocular implantable steroid delivery systems, factors influencing side effects, and future perspectives for ocular corticosteroid therapy.

MLL2 regulates glucocorticoid receptor-mediated transcription of ENACα in human retinal pigment epithelial cells

Glucocorticoids require the glucocorticoid receptor (GR), a type of ligand-dependent nuclear receptor to transmit their downstream effects. Upon glucocorticoid binding, GR associates with glucocorticoid response elements (GREs) and recruits other transcriptional coregulators to activate or repress target gene transcription. Many SET-domain family proteins have been demonstrated to contribute to GR-mediated transcriptional activity. However, whether histone H3K4-specific methyltransferase plays a cell-type-specific role in GR transcriptional regulation remains poorly understood. In this report, we examined MLL2 (KMT2D), a histone-lysine methyltransferase that catalyzes histone H3 lysine 4 methylation (H3K4me). Furthermore, we demonstrated that MLL2 specifically regulates the transcription of some GR target genes (e.g., ENACα and FLJ20371) in ARPE-19 cells, but has no effect in A549 cells. Mechanistically, co-immunoprecipitation assays revealed that MLL2 is associated with GR in a ligand-independent manner in APRE-19 cells. Moreover, chromatin immunoprecipitation analyses demonstrated that MLL2 could co-occupy glucocorticoid response elements (GREs) of GR target genes along with GR following Dex stimulation. Finally, the FAIRE-qPCR results illustrated that MLL2 is pivotal in establishing chromatin structure accessibility at the GREs of ARPE-19 specific genes in the presence of Dex. Taken together, our study determined that MLL2 regulates GR-mediated transcription in a cell-type-specific manner, and we provide a molecular mechanism to explain the specific role of MLL2 in regulating GR target gene expression in ARPE-19 cells.

Leveraging Nuclear Receptors as Targets for Pathological Ocular Vascular Diseases

Vasculogenesis and angiogenesis are physiological mechanisms occurring throughout the body. Any disruption to the precise balance of blood vessel growth necessary to support healthy tissue, and the inhibition of abnormal vessel sprouting has the potential to negatively impact stages of development and/or healing. Therefore, the identification of key regulators of these vascular processes is critical to identifying therapeutic means by which to target vascular-associated compromises and complications. Nuclear receptors are a family of transcription factors that have been shown to be involved in modulating different aspects of vascular biology in many tissues systems. Most recently, the role of nuclear receptors in ocular biology and vasculopathies has garnered interest. Herein, we review studies that have used in vitro assays and in vivo models to investigate nuclear receptor-driven pathways in two ocular vascular diseases associated with blindness, wet or exudative age-related macular degeneration, and proliferative diabetic retinopathy. The potential therapeutic targeting of nuclear receptors for ocular diseases is also discussed.

Spatial immobilization of endogenous growth factors to control vascularization in bone tissue engineering

An engineered biofunctional system comprises endogenous BMP-2 and VEGF bound in a parallel pattern. It successfully enabled obtaining the spatial osteogenic and angiogenic differentiation of human hBM-MSCs under basal culture conditions.

Enhancing the efficacy of fluocinolone acetonide by encapsulating with PLGA nanoparticles and conjugating with linear PEG polymer

Fluocinolone acetonide (FA), a glucocorticoid is used to treat inflammation in the posterior segment of the eye. Due to short half-life and body clearance, it will not be able to give therapeutic effect for long time with a single injection. Formulating FA nanoparticles (NPs) or PEG conjugates can be an effective way to overcome these disadvantages. We prepared two formulations, FA loaded in PLGA nanoparticles (NPs-FA) and FA conjugated to linear PEG (PEG-FA). The NPs-FA were characterised for size and zeta potential using particle size analyser and shape and morphology by using scanning electron microscope (SEM). The amount of drug loaded per mg of NPs and in-vitro release of FA from NPs were calculated using reverse phase high pressure liquid chromatography (RP-HPLC). NPs synthesis was optimized with factorial and Response Surface Methodology (RSM). Chemically synthesized PEG-FA conjugates were characterized using H-NMR and purity of the conjugate was analysed using RP-HPLC. Visualization of cellular uptake of NPs was done by coumarin-6 loaded NPs under fluorescent microscope. RAW 264.7 macrophages were treated with NPs-FA and PEG-FA conjugates to study their effectiveness in inhibiting TNF-α levels compared to free FA treatment. Stability test confirmed that FA is more stable within NPs than in free form. Particle size and zeta potential were found to be 183.6 ± 12.47nm and -25.6 ± 4.4mV, respectively. 149.58 ± 11.3µg of FA was encapsulated per mg of NPs and 61 µg of FA was present per mg of PEG-FA conjugate. In vitro drug release study showed a sustained release of FA from the NPs for a period of 30 days. Fluorescent microscope images showed uptake of NPs by RAW 264.7 cells. TNF-α assay confirmed that substantial inhibition of TNF-α levels from both formulations compared to free FA. From the results, we conclude that new formulations will greatly reduce drug dosage and frequency of administration for long term treatment of inflammation in posterior part of the eye.

Handheld laser devices and laser-induced retinopathy (LIR) in children: an overview of the literature

Handheld laser devices are easily available to purchase through the internet and unregulated marketplaces at a relatively low cost. They are particularly attractive to children as they are seen as 'high tech', brightly coloured, and known to be able to burn holes in objects such as balloons. There is a widespread lack of knowledge about the risks of viewing the beam emanating directly from handheld lasers, and particularly those with high-output powers. The number of reported laser induced retinopathy (LIR) injuries in children is on the increase in the United Kingdom and represents a major public health issue. The number of individuals affected by LIR is likely to be underestimated owing to lack of presentation to health professionals, general poor awareness and non-reporting by children after the incident. The presentation of LIR is highly variable and dependent on many factors including type of laser, length of exposure and how it is administered. In this article, we review the features of retinal damage associated with inadvertent or deliberate laser administration using a handheld laser device. We highlight the importance of educating the wider public about this increasing problem; children who play with these devices are usually completely unaware of the long-term consequences of laser damage to the eye. It is also important that the features of LIR are recognised by health professionals involved in eye care as they can be mistaken for retinal dystrophies, particularly if the history of laser exposure is not volunteered or elicited.

Effect of intravitreal or sub-tenon triamcinolone acetonide injection at completion of vitrectomy on peripheral retinochoroidal thickness in eyes with proliferative diabetic retinopathy

The effect of triamcinolone acetonide (TA) on the peripheral retinochoroidal thickness was determined after pars plana vitrectomy (PPV) with scatter photocoagulation in eyes with proliferative diabetic retinopathy. The peripheral retinochoroidal thickness was measured at 5 mm from the limbus in the four quadrants using anterior segment optical coherence tomography before, and 3 days, and 1 and 2 weeks after the surgery. The total peripheral thickness was significantly thicker than the baseline thickness after PPV alone (P < 0.001; 18 eyes), PPV combined with intravitreal TA injection (IVTA; P = 0.011; 19 eyes), and PPV combined with sub-tenon TA injection (STTA; P = 0001; 23 eyes). The total peripheral thickness in the PPV group at 3 days after surgery was significantly thicker than that of the PPV + IVTA (P = 0.015) and of the PPV + STTA groups (P = 0.016). Multiple linear regression analyses showed that the injection of TA by the two routes and the number of photocoagulation burns were significantly correlated with the total peripheral thicknesses at 3 days after the surgery. The results indicate that the PPV with large number of intraoperative scatter photocoagulation burns caused an increase in the total peripheral thickness and an administration of either IVTA and STTA can reduced the degree of thickening.

Intravitreal fluocinolone acetonide implant (ILUVIEN®) for diabetic macular oedema: a literature review

Diabetic macular oedema (DMO) is a common complication of diabetic retinopathy and may lead to severe visual loss. In this review, we describe the pathophysiology of DMO and review current therapeutic options such as macular laser photocoagulation, anti-vascular endothelial growth factor agents, and steroid implants with a focus on the new fluocinolone acetonide implant, ILUVIEN®. The results of the Fluocinolone Acetonide in Diabetic Macular Edema (FAME) studies are also presented together with the results of real-world studies to support the clinical use of ILUVIEN® in achieving efficient resolution of DMO and improving vision and macular anatomy in this challenging group of patients.

Laser Pointer-Induced Maculopathy: More Than Meets the Eye

PURPOSE

To describe the clinical findings in patients with laser-induced retinal injury.

METHODS

Consecutive patients presenting to a tertiary center between January 2014 and December 2015 following inadvertent ocular exposure to a laser pointer were included. Evaluation included a full ophthalmic examination and spectral-domain optical coherence tomography (SD-OCT).

RESULTS

Seven young patients (8 eyes) were identified. Their mean age was 18.7 years (median: 16 years; range: 12 to 36 years). In most cases, patients were exposed for several seconds to a 5-mW green laser. At presentation, all patients complained of a central/paracentral scotoma. Snellen best corrected visual acuity (BCVA) at presentation ranged from counting fingers to 6/6. In 5 eyes, a round, well-defined deep yellowish-orange discoloration at the level of the retinal pigment epithelium in the foveola, ranging from 150 to 350 μm in diameter, was noted on ophthalmoscopic examination. Additional findings were macular subhyaloid hemorrhage in 2 eyes and a full-thickness macular hole with cystoid macular edema in 1 eye. In all cases, baseline SD-OCT revealed disruption involving the photoreceptor inner segment/outer segment junction/ellipsoid zone band, and extended toward the inner aspect of the retinal pigment epithelium band, ranging from focal interruption to extensive full-thickness macular hole. All patients received oral corticosteroid treatment with prednisone (0.5 to 1 mg/kg). Follow-up ranged between 2 and 12 months. Over time, improvement in visual acuity to 6/8 and 6/6 was noted in all eyes but one, which remained poor at counting fingers from 2 meters. The visual improvement was associated with complete or near-complete restoration of the integrity of macular structure noted on SDOCT.

CONCLUSIONS

Commercial handheld laser pointers may inflict notable macular injury and damage vision permanently. Although good visual recovery was often noted, access to commercially available laser devices is potentially hazardous, especially to minors, and public awareness should be raised. [J Pediatr Ophthalmol Strabismus. 2018;55(5):312-318.].

Identification of fluocinolone acetonide to prevent paclitaxel-induced peripheral neuropathy

Paclitaxel (PTX) is among the most commonly used cancer drugs that cause chemotherapy-induced peripheral neuropathy (CIPN), a debilitating and serious dose-limiting side effect. Currently, no drugs exist to prevent CIPN, and symptomatic therapy is often ineffective. In order to identify therapeutic candidates to prevent axonal degeneration induced by PTX, we carried out a phenotypic drug screening using primary rodent dorsal root ganglion sensory neurons. We identified fluocinolone acetonide as a neuroprotective compound and verified it through secondary screens. Furthermore, we showed its efficacy in a mouse model of PTX-induced peripheral neuropathy and confirmed with four different cancer cell lines that fluocinolone acetonide does not interfere with PTX's antitumor activity. Our study identifies fluocinolone acetonide as a potential therapy to prevent CIPN caused by PTX.

Effect of intravitreal triamcinolone acetonide injection at the end of vitrectomy for vitreous haemorrhage related to proliferative diabetic retinopathy

Background/Aims

To investigate whether intravitreal injection of triamcinolone acetonide (IVTA) combined with vitrectomy prevents postoperative inflammation in patients with vitreous haemorrhage (VH) due to proliferative diabetic retinopathy (PDR).

Methods

This prospective, multicentre, randomised study conducted at seven sites in Japan enrolled patients diagnosed as having VH following PDR. Patients underwent vitrectomy with (IVTA+VIT group) or without (VIT group) IVTA at the end of the surgery. Anterior flare intensity (AFI), central retinal thickness (CRT), best-corrected visual acuity (BCVA) and intraocular pressure (IOP) were measured before and at 3 days, 1 week, 1, 3 and 6 months after surgery and compared.

Results

Number of patients who completed 6 months of follow-up was 40 and 41 in VIT group and IVTA+VIT group, respectively. AFI was significantly higher in the VIT group than in the IVTA+VIT group at 3 days (P=0.033), 1 week (P=0.019) and 1 month (P=0.037). There were no significant differences in CRT, BCVA and IOP between the groups through the observational periods. In the cases with macular oedema >350 µm of CRT at 3 days, CRT was significantly lower in the IVTA+VIT group than in the VIT group at 1 month (P=0.041).

Conclusions

IVTA combined with vitrectomy and cataract surgery contributed to inhibit the postoperative inflammation in patients with VH due to PDR. The effect of IVTA in the reduction of diabetic macular oedema may be limited to the early stage after surgery.

Trial registration number

UMIN000020376, Post-results.

Fluocinolone Acetonide Intravitreal Implant 0.19 mg (ILUVIEN®): A Review in Diabetic Macular Edema

Fluocinolone acetonide intravitreal implant 0.19 mg (ILUVIEN^®) is a nonbiodegradable, injectable, corticosteroid implant that is approved in several countries, including the USA, for the treatment of diabetic macular edema (DME). ILUVIEN^® releases fluocinolone acetonide at an initial rate of 0.25 µg/day (average rate 0.2 µg/day) and lasts 36 months. In the two pooled pivotal FAME trials in patients with DME previously treated with macular laser photocoagulation, fluocinolone acetonide intravitreal implant 0.2 µg/day was significantly more effective than sham injection with respect to the proportion of patients with an improvement from baseline in best-corrected visual acuity of ≥15 letters at 24 months (primary endpoint). This therapeutic effect was maintained at 36 months. The implant also significantly decreased foveal thickness at 24 months. FAME study results are broadly supported by real-world studies in patients with chronic DME considered insufficiently responsive to available therapies. Consistent with corticosteroid class-specific adverse events, cataract and elevated intraocular pressure (IOP) were the most common adverse events with the fluocinolone acetonide intravitreal implant. Raised IOP was treated with medications in most patients, with <5% requiring incisional IOP-lowering surgery. In the USA, fluocinolone acetonide intravitreal implant should be used only in patients who have been previously treated with a course of corticosteroids and did not have a clinically significant increase in IOP. Available data indicate that fluocinolone acetonide intravitreal implant 0.19 mg is a useful option for the treatment of DME in these patients.

Long-term Effects of Intravitreal 0.19 mg Fluocinolone Acetonide Implant on Progression and Regression of Diabetic Retinopathy

OBJECTIVE

To investigate the effects of fluocinolone acetonide (FAc) on the progression to proliferative diabetic retinopathy (PDR) and the impact of FAc on changes in Early Treatment Diabetic Retinopathy Study (ETDRS) diabetic retinopathy (DR) severity scale (DRSS) grade during the Fluocinolone Acetonide in Diabetic Macular Edema (FAME) A and B Phase III clinical trials.

DESIGN

Post hoc analysis of data from the 36-month prospective, randomized, FAME A and B trials.

PARTICIPANTS

Patients with diabetic macular edema (DME) who received sham control or FAc 0.2 or 0.5 μg/day.

METHODS

A masked reading center (University of Wisconsin-Madison) determined DRSS grade and retinal perfusion status using standard 7-field stereo fundus photography and fluorescein angiography, respectively. Retinopathy changes over time were determined by DRSS step differences from baseline to month 36. Pairwise comparisons between the 3 treatment groups were performed using a log-rank test without adjustment for covariates, with the primary comparison between sham control and 0.2 μg/day FAc.

MAIN OUTCOME MEASURES

Study eye progression to PDR based on a composite clinical outcome of (1) progression from nonproliferative diabetic retinopathy (NPDR) to PDR based on graded fundus photographs, (2) panretinal photocoagulation (PRP), or (3) pars plana vitrectomy (PPV) for PDR; and study eye changes on the DRSS.

RESULTS

In the integrated FAME data set, compared with sham control-treated subjects, time to first PDR event was significantly delayed in subjects treated with FAc (P < 0.001), and this effect was confirmed in subgroups with more severe DR and chronic DME at baseline. In addition, subjects with retinal nonperfusion at baseline showed greater reduction in progression to PDR with FAc treatment. Both FAc dosages demonstrated statistically significant improvements in mean DR severity compared with sham treatment at months 6, 12, and 18. Numerically more subjects who received FAc experienced 2-or-more- or 3-or-more-step improvements in DR severity compared with subjects who received sham; conversely, fewer subjects treated with FAc experienced 2-or-more- or 3-or-more-step worsening in DR severity. The 3-or-more-step improvement with 0.5 μg/day FAc was statistically significantly different from sham control.

CONCLUSIONS

In subjects with DME, sustained intraocular delivery of FAc slows development of PDR and slows progression of diabetic retinopathy.

Crosstalk between Aryl Hydrocarbon Receptor and Glucocorticoid Receptor in Human Retinal Pigment Epithelial Cells

The aryl hydrocarbon receptor (AHR) is known to mediate the cellular reaction involved in processing environmental contaminants and, ultimately, preventing accumulation of unfavorable extra lipids and proteins. Glucocorticoid receptor (GR) mediates the expression of genes associated with anti-inflammatory properties. Because AHR and GR are closely related in lipid metabolic dysregulation and inflammation, we speculate that AHR and GR may play a crucial role in AMD pathogenesis and focus on their crosstalk in human retinal pigment epithelial cells (ARPE-19). However, how AHR and GR regulate each other's signaling pathways is still poorly understood. In this research, we demonstrate that GR attenuates AHR-mediated gene expression by inhibition of nuclear translocation of AHR mediated by TCDD. Chromatin immunoprecipitation analysis demonstrated that GR repress AHR recruitment and chromatin accessibility response to TCDD + Dex treatment leading to repression of AHR target genes. In contrast, AHR facilitates GR-mediated expression in ARPE-19. AHR increases GR recruitment on GRE of GR target genes. Coimmunoprecipitation assay revealed that AHR is associated with GR in ARPE-19 cells and the interaction is enhanced by the addition of TCDD and Dex. Taken together, these studies provide a molecular mechanism of crosstalk between AHR and GR in target gene expression in ARPE-19 cells.

Sustained-release fluocinolone acetonide intravitreal insert for macular edema: clinical pharmacology and safety evaluation

INTRODUCTION

Inflammation plays a key role in the pathological processes leading to macular edema. Sustained release, low-dose intraocular corticosteroid delivery devices provide long-term anti-inflammatory therapy. Recently, a novel fluocinolone acetonide intravitreal insert (FAi, Iluvien), has been introduced with promising long-term results in the treatment of macular edema.

AREAS COVERED

An extensive review of the literature in the English language was performed to provide comprehensive information on the pharmacological properties of FAi and its safety and efficacy data from various multi-center randomized clinical trials.

EXPERT OPINION

The FAc, Retisert is a sustained-release device that is surgically implanted in the vitreous and has been approved by the US FDA for the treatment of non-infectious intermediate, posterior or panuveitis. FAi was developed after FAc and is an intravitreal corticosteroid delivery system that allows controlled release of therapeutic levels of fluocinolone acetonide (FA). Initial efficacy and safety data suggest that this delivery system maintains clinical effectiveness for up to 3 years after a single delivery of the device. This second-generation fluocinolone delivery device has shown superior safety results in clinical trials compared to the previous version of the higher dose FAc (0.59 mg). Sustained delivery preparations may help to reduce the treatment burden and its associated risks by decreasing the frequency of intravitreal injections. However, much needs to be learnt from additional clinical trials, post-marketing surveillance and results of extension studies. Concerns of intravitreal corticosteroids, such as cataract and increase in intraocular pressure, remain major challenges for this therapeutic strategy.

Intracellular delivery of dendrimer triamcinolone acetonide conjugates into microglial and human retinal pigment epithelial cells

Triamcinolone acetonide (TA) is a potent, intermediate-acting, steroid that has anti-inflammatory and anti-angiogenic activity. Intravitreal administration of TA has been used for diabetic macular edema, proliferative diabetic retinopathy and exudative age-related macular degeneration (AMD). However, the hydrophobicity, lack of solubility, and the side effects limit its effectiveness in the treatment of retinal diseases. In this study, we explore a PAMAM dendrimer-TA conjugate (D-TA) as a potential strategy to improve intracellular delivery and efficacy of TA to target cells. The conjugates were prepared with a high drug payload (∼ 21%) and were readily soluble in saline. Compared to free TA, D-TA demonstrated a significantly improved toxicity profile in two important target [microglial and human retinal pigment epithelium (RPE)] cells. The D-TA was ∼ 100-fold more effective than free TA in its anti-inflammatory activity (measured in microglia), and in suppressing VEGF production (in hypoxic RPE cells). Dendrimer-based delivery may improve the efficacy of TA towards both its key targets of inflammation and VEGF production, with significant clinical implications.

Fluocinolone acetonide partially restores the mineralization of LPS-stimulated dental pulp cells through inhibition of NF-κB pathway and activation of AP-1 pathway

BACKGROUND AND PURPOSE

Fluocinolone acetonide (FA) is commonly used as a steroidal anti-inflammatory drug. We recently found that in dental pulp cells (DPCs) FA has osteo-/odonto-inductive as well as anti-inflammatory effects. However, the mechanism by which FA induces these effects in DPCs is poorly understood.

EXPERIMENTAL APPROACH

The effect of FA on the mineralization of DPCs during inflammatory conditions and the underlying mechanism were investigated by real-time PCR, Western blot, EMSA, histochemical staining, immunostaining and pathway blockade assays.

KEY RESULTS

FA significantly inhibited the inflammatory response in LPS-treated DPCs not only by down-regulating the expression of pro-inflammation-related genes, but also by up-regulating the expression of the anti-inflammatory gene PPAR-γ and mineralization-related genes. Moreover, histochemical staining and immunostaining showed that FA could partially restore the expressions of alkaline phosphatase, osteocalcin and dentin sialophosphoprotein (DSPP) and mineralization in LPS-stimulated DPCs. Real-time PCR and Western blot analysis revealed that FA up-regulated DSPP and runt-related transcription factor 2 expression by inhibiting the expression of phosphorylated-NF-κB P65 and activating activator protein-1 (AP-1) (p-c-Jun and Fra-1). These results were further confirmed through EMSA, by detection of NF-κB DNA-binding activity and pathway blockade assays using a NF-κB pathway inhibitor, AP-1 pathway inhibitor and glucocorticoid receptor antagonist.

CONCLUSIONS AND IMPLICATIONS

Inflammation induced by LPS suppresses the mineralization process in DPCs. FA partially restored this osteo-/odonto-genesis process in LPS-treated DPCs and had an anti-inflammatory effect through inhibition of the NF-κB pathway and activation of the AP-1 pathway. Hence, FA is a potential new treatment for inflammation-associated bone/teeth diseases.

Emerging roles for nuclear receptors in the pathogenesis of age-related macular degeneration

Age-related macular degeneration (AMD) is the leading cause of vision loss in the elderly in the Western world. Over the last 30 years, our understanding of the pathogenesis of the disease has grown exponentially thanks to the results of countless epidemiology, genetic, histological, and biochemical studies. This information, in turn, has led to the identification of multiple biologic pathways potentially involved in development and progression of AMD, including but not limited to inflammation, lipid and extracellular matrix dysregulation, and angiogenesis. Nuclear receptors are a superfamily of transcription factors that have been shown to regulate many of the pathogenic pathways linked with AMD and as such they are emerging as promising targets for therapeutic intervention. In this review, we will present the fundamental phenotypic features of AMD and discuss our current understanding of the pathobiological disease mechanisms. We will introduce the nuclear receptor superfamily and discuss the current literature on their effects on AMD-related pathophysiology.

Emerging drugs for diabetic macular edema

INTRODUCTION

Diabetic macular edema (DME) is the most common cause of visual impairment due to diabetic retinopathy. The treatment of DME has recently undergone a paradigm shift. Traditionally, photocoagulation was standard treatment, but pharmacologic therapies are becoming increasingly used for this purpose. All currently available drug therapies for DME are either anti-VEGF agents or corticosteroids.

AREAS COVERED

The pathogenesis of DME involves angiogenesis, inflammation and oxidative stress. The scientific rationale to treat DME through the pharmacologic blockade of VEGF and other pro-angiogenic factors is discussed. The fluocinolone insert is approved for the treatment of DME in several European countries, but not in the US at this time. Some medications that are already approved for other retinal diseases, most prominently aflibercept and the dexamethasone delivery system, have recently obtained approval for DME in the US. Other compounds are being studied in earlier-phase clinical trials.

EXPERT OPINION

Pharmacologic treatment of DME will likely become increasingly used, especially for patients with edema involving the fovea. At this time, the two main classes of medication for treatment of DME are anti-VEGF agents and corticosteroids. As we continue to collect clinical trials data, the precise role of individual agents, and the continuing role for photocoagulation, will become more clear.

ChIP-Enrich: gene set enrichment testing for ChIP-seq data

Gene set enrichment testing can enhance the biological interpretation of ChIP-seq data. Here, we develop a method, ChIP-Enrich, for this analysis which empirically adjusts for gene locus length (the length of the gene body and its surrounding non-coding sequence). Adjustment for gene locus length is necessary because it is often positively associated with the presence of one or more peaks and because many biologically defined gene sets have an excess of genes with longer or shorter gene locus lengths. Unlike alternative methods, ChIP-Enrich can account for the wide range of gene locus length-to-peak presence relationships (observed in ENCODE ChIP-seq data sets). We show that ChIP-Enrich has a well-calibrated type I error rate using permuted ENCODE ChIP-seq data sets; in contrast, two commonly used gene set enrichment methods, Fisher's exact test and the binomial test implemented in Genomic Regions Enrichment of Annotations Tool (GREAT), can have highly inflated type I error rates and biases in ranking. We identify DNA-binding proteins, including CTCF, JunD and glucocorticoid receptor α (GRα), that show different enrichment patterns for peaks closer to versus further from transcription start sites. We also identify known and potential new biological functions of GRα. ChIP-Enrich is available as a web interface (http://chip-enrich.med.umich.edu) and Bioconductor package.

Trophic factors in the pathogenesis and therapy for retinal degenerative diseases

Trophic factors are endogenously secreted proteins that act in an autocrine and/or paracrine fashion to affect vital cellular processes such as proliferation, differentiation, and regeneration, thereby maintaining overall cell homeostasis. In the eye, the major contributors of these molecules are the retinal pigment epithelial (RPE) and Müller cells. The primary paracrine targets of these secreted proteins include the photoreceptors and choriocapillaris. Retinal degenerative diseases such as age-related macular degeneration and retinitis pigmentosa are characterized by aberrant function and/or eventual death of RPE cells, photoreceptors, choriocapillaris, and other retinal cells. We discuss results of in vitro and in vivo animal studies in which candidate trophic factors, either singly or in combination, were used in an attempt to ameliorate photoreceptor and/or retinal degeneration. We also examine current trophic factor therapies as they relate to the treatment of retinal degenerative diseases in clinical studies.

Intravitreal Corticosteroids in the Management of Diabetic Macular Edema

Diabetic macular edema (DME) remains an important worldwide cause of visual loss. Corticosteroids have a role in the treatment of some patients with advanced or recurrent DME. The best studied steroids for this indication are triamcinolone acetonide, dexamethasone, and fluocinolone acetonide. All steroids are associated with risks of cataract and intraocular pressure elevation. In addition, intravitreal injection of any medication is associated with risks of infectious endophthalmitis, which has led to the investigation of various extended-release steroid implants. At this time, no steroid is approved by the United States Food and Drug Administration (FDA) for the treatment of DME.

RETRACTED: Influence of choroidal neovascularization and biodegradable polymeric particle size on transscleral sustained delivery of triamcinolone acetonide

PURPOSE

One objective of this study was to determine whether polymeric nanoparticles and/or microparticles sustain transscleral choroidal and retinal delivery of triamcinolone acetonide (TA) for two months in therapeutically effective concentrations after single periocular administration. Another objective of this study was to assess the influence of choroidal neovascularization on transscleral delivery of TA.

METHODS

Polymeric nano- and micro-particles of TA were prepared by o/w emulsion-solvent evaporation method using poly-l-lactide (PLA). Particles were characterized for drug loading, size, surface morphology, and the in vitro drug release profile. Choroidal neovascularization (CNV) was induced in brown Norway (BN) rats using a 532 nm diode argon laser and the CNV induction was assessed using fluorescein angiography. In vivo delivery was assessed in control and CNV induced rats at 2 months after periocular injection of TA loaded nano- or micro-particle suspension, or plain TA suspension in PBS (pH 7.4). Ocular tissue levels of TA were estimated using LC-MS/MS following liquid-liquid extraction of drug from tissue samples. Nile red loaded microparticles entrapped in periocular tissue at the end of the study was visualized using scanning electron microscopy and confocal microscopy. Inhibitory effect of TA on VEGF secretion was evaluated in ARPE-19 cells.

RESULTS

Triamcinolone acetonide-PLA nano- (551 nm) and micro-particles (2090 nm), with 14.7 and 29.5% drug loading, respectively, sustained in vitro TA release for about 45 and 120 days. After subconjunctival injection, microparticles were able to sustain the delivery in all intraocular tissues for 2 months; whereas no drug levels were detected for TA loaded nanoparticles and plain suspension of TA. Intraocular delivery of TA from microparticles was higher in CNV induced rats when compared to control rats. Significant amount of microparticles remained in periocular tissue at 2 months after injection, and maintained spherical shape. TA decreased VEGF secretion by 50% at 0.07 μM. At the end of the in vivo study, choroid-RPE and retina TA levels in CNV induced rats were 16- and 5-fold higher than the IC(50) for VEGF secretion.

CONCLUSIONS

Single periocular injection of polymeric microparticles but not nanoparticles sustained effective levels of TA in choroid-RPE and retina for 2 months, with the TA delivery being greater in CNV induced rats than the control rats.

Recent advances in ophthalmic drug delivery

Topical ocular drug bioavailability is notoriously poor, in the order of 5% or less. This is a consequence of effective multiple barriers to drug entry, comprising nasolacrimal drainage, epithelial drug transport barriers and clearance from the vasculature in the conjunctiva. While sustained drug delivery to the back of the eye is now feasible with intravitreal implants such as Vitrasert (-6 months), Retisert (-3 years) and Iluvien (-3 years), currently there are no marketed delivery systems for long-term drug delivery to the anterior segment of the eye. The purpose of this article is to summarize the resurgence in interest to prolong and improve drug entry from topical administration. These approaches include mucoadhesives, viscous polymer vehicles, transporter-targeted prodrug design, receptor-targeted functionalized nanoparticles, iontophoresis, punctal plug and contact lens delivery systems. A few of these delivery systems might be useful in treating diseases affecting the back of the eye. Their effectiveness will be compared against intravitreal implants (upper bound of effectiveness) and trans-scleral systems (lower bound of effectiveness). Refining the animal model by incorporating the latest advances in microdialysis and imaging technology is key to expanding the knowledge central to the design, testing and evaluation of the next generation of innovative ocular drug delivery systems.

Evaluation of the transforming growth factor-beta activity in normal and dry eye human tears by CCL-185 cell bioassay

PURPOSE

To develop a new bioassay method using human lung epithelial cells (CCL-185) to assess activity of transforming growth factor beta (TGF-beta) in human tear fluid from normal subjects and patients with dry eye.

METHODS

Two epithelial cell lines, mink lung cells (CCL-64) and human lung cells (CCL-185), were compared to detect the active form of TGF-beta by BrdU incorporation (quantitation of cell DNA synthesis) and WST assay (metabolic activity of viable cells). The effect of TGF-beta on the growth of CCL-185 cells was observed microscopically. Human tears from normal control subjects and patients with dry eye (DE) with and without Sjögren syndrome were evaluated for TGF-beta concentration by Luminex microbead assay, and TGF-beta activity by the CCL-185 cell growth inhibition bioassay.

RESULTS

The metabolic activity of viable CCL-185 cells, measured by WST, was shown to be proportional to the TGF-beta1 concentration (R = 0.919) and confirmed by BrdU assay (R = 0.969). Compared with CCL-185, metabolic activity of viable cells and DNA synthesis, measured by WST and BrdU incorporation assays, were shown to be less proportional to the TGF-beta1 concentration in the CCL-64 line (R = 0.42 and 0.17, respectively). Coincubation with human anti-TGF-beta1 antibody (MAB-240) yielded a dose-dependent inhibition of TGF-beta1 (0.3 ng/mL) activity. CCL-185 cell growth observed microscopically was noted to decrease in response to increasing TGF-beta1 concentrations. Levels of immuodetectable TGF-beta1 and TGF-beta2 were similar in normal and DE tears. TGF-beta bioactivity in DE human tears measured by the CCL-185 cells assay was found to be higher (9777.5 +/- 10481.9 pg/mL) than those in normal controls (4129.3 +/- 1342.9 pg/mL) (P < 0.05). Among patients with DE, TGF-beta bioactivity was highest in those with Sjögren syndrome. Approximately, 79.1% of TGF-beta in DE tears and 37.6% TGF-beta in normal tears were found to be biologically active.

CONCLUSIONS

The CCL-185 cell assay was found to be a suitable tool for assessing TGF-beta activity in human tears. Tear TGF-beta bioactivity increases in DE, particularly in Sjögren syndrome, where elevated levels of TGF-beta1 transcripts in the conjunctival epithelium have been previously detected.

The PKCbeta/HuR/VEGF pathway in diabetic retinopathy

We investigated whether the diabetes-related PKCbeta activation affects VEGF expression through the mRNA-stabilizing human embryonic lethal abnormal vision (ELAV) protein, HuR, in the retina of streptozotocin (STZ)-induced diabetic rats. Diabetes was induced in rats by STZ injection. Retinal tissues were processed to detect PKCbetaI, PKCbetaII, VEGF and HuR contents, as well as HuR phosphorylation. Immunoprecipitation coupled to RT-PCR was employed to evaluate HuR binding to VEGF mRNA in RiboNucleoProteic (RNP) complexes. Statistical analysis was performed by ANOVA followed by an appropriate post hoc comparison test. Following experimental diabetes PKCbetaI and PKCbetaII levels were increased compared to sham; there was also a PKC-mediated phosphorylation/activation of HuR. These effects were blunted by the in vivo co-administration of a selective PKCbeta inhibitor. A specific binding between the HuR protein and the VEGF mRNA was also detected. The PKCbeta/HuR activation was accompanied by enhanced VEGF protein expression that was, again, blunted by the PKCbeta inhibitor. These findings first demonstrate the activation, in the retina, of the PKCbeta/HuR/VEGF pathway following experimental diabetes and disclose a new potential pharmacological target to counteract pathologies implicating VEGF deregulation, such as diabetic retinopathy.