921 resultados para Ocular inflammation


Relevância:

20.00% 20.00%

Publicador:

Resumo:

We have developed a thrombin-sensitive polymeric photosensitizer prodrug (T-PS) to selectively image and eradicate inflammatory lesions in rheumatoid arthritis (RA). Thrombin is a serine protease up-regulated in synovial tissues of rheumatoid arthritis (RA) patients. T-PS consists of a polymeric backbone, to which multiple photosensitizer (PS) units are tethered via short thrombin-cleavable peptide linkers. Fluorescence emission and phototoxicity of the prodrug are efficiently quenched due to the interaction of neighboring photosensitizer units. The prodrug is passively delivered to the inflammation site via the enhanced permeability and retention (EPR) effect. Subsequent site-selective proteolytic cleavage of the peptide linkers restores its photoactivity by increasing the mutual distance between PS. Whole animal imaging in murine collagen-induced arthritis, an experimental model of RA revealed a dose-dependent fluorescence increase in arthritic paws after systemic prodrug injection. In addition, administration of T-PS resulted in much higher fluorescence selectivity for arthritic joints as compared to the free PS. Irradiation of the arthritic joints induced light dose dependent phototoxic effects such as apoptosis, vascular damage and local hemorrhage. Long-term observations showed complete regression of the latter. Irradiated non-arthritic tissues or non-irradiated arthritic tissues showed no histological effects after photodynamic therapy with T-PS. This illustrates that T-PS can localize inflammatory lesions with excellent selectivity and induce apoptosis and vascular shut down after irradiation.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Due to its small size and particular isolating barriers, the eye is an ideal target for local therapy. Recombinant protein ocular delivery requires invasive and painful repeated injections. Alternatively, a transfected tissue might be used as a local producer of transgene-encoded therapeutic protein. We have developed a nondamaging electrically mediated plasmid delivery technique (electrotransfer) targeted to the ciliary muscle, which is used as a reservoir tissue for the long-lasting expression and secretion of therapeutic proteins. High and long-lasting reporter gene expression was observed, which was restricted to the ciliary muscle. Chimeric TNF-alpha soluble receptor (hTNFR-Is) electrotransfer led to elevated protein secretion in aqueous humor and to drastic inhibition of clinical and histological inflammation scores in rats with endotoxin-induced uveitis. No hTNFR-Is was detected in the serum, demonstrating the local delivery of proteins using this method. Plasmid electrotransfer to the ciliary muscle, as performed in this study, did not induce any ocular pathology or structural damage. Local and sustained therapeutic protein production through ciliary muscle electrotransfer is a promising alternative to repeated intraocular protein administration for a large number of inflammatory, degenerative, or angiogenic diseases.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The risk of malignant B cell lymphoma is increased in Sjögren's syndrome (SS). Orbital localization seems infrequent. We report 4 cases of malignant lymphoma (ML) occurring in 4 women aged 47 to 77 years, with primary SS in 3 cases, located to the conjunctiva in 2 cases, the lacrymal gland in 1 case and the eyelid in 1 case. The interval between the diagnosis of SS and orbital ML varied from 6 months to 15 years. All 4 lymphomas were of the B cell type, low histopathologic grade, with monoclonal gammopathy in 1 case. Extraocular lymphoma was initially present in 1 case. ML remained localized in 2 cases with a follow-up of 4 and 6 years. Two patients treated by excisional biopsy alone are in complete remission 3 and 6 years later. The 2 other patients treated with orbital radiotherapy and chemotherapy died rapidly (transformation into a high grade malignancy in 1 case). We conclude that clinical, immunopathologic features, as well as prognosis and treatment of ocular adnexa ML in SS are similar to those of primary ML without SS.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background : Monosodium urate (MSU) crystals stimulate the productionof interleukin-1b (IL-1b), a potent inflammatory cytokine. Targeted IL-1b blockade with canakinumab, a fully human monoclonal anti-IL-1b antibody, is a novel treatment for gouty arthritis. Its effects on pain and inflammation in acute gouty arthritis flares were compared with triamcinolone acetonide (TA). TA has been shown to be effective in the treatment of acute gouty arthritis flares.Methods : This was an 8-week, dose-ranging, multicenter, blinded, active-controlled trial. Patients _18 to _80 years with an acute gouty arthritis flare, refractory to or contraindicated to NSAIDs and/or colchicine were randomized to one subcutaneous dose of canakinumab (10, 25, 50, 90, or 150 mg; n¼143) or one intramuscular dose of TA (40 mg; n¼57). Primary outcome was pain intensity at 72 hours post dose on VAS scale (0-100 mm). Secondary outcomes included Creactive protein (CRP), serum amyloid A (SAA), and physician's assessment of tenderness, swelling and erythema of target joint at 72 hours, 7 days, 4 and 8-weeks post dose.Results : 191/200 patients completed the study. Canakinumab showed a statistically significant dose response at 72 hours. The 150mg dose group reached superior pain relief compared to TA group starting from 24 hours as previously reported. At 72 hours post dose, 78% of canakinumab 150mg treated patients achieved _75% and 96% achieved _50% reduction in pain from baseline. In contrast, 45% and 61% of patients treated with TA achieved _75% and _50% pain reduction, respectively. Median CRP/SAA levels were normalized by Day 7 for all canakinumab doses above 10mg and remained below the upper limit of normal [(ULN): CRP 3.0 mg/L; SAA 6.7 mg/L)] for rest of the study. In TA group, median CRP levels remained above the ULN throughout the study while median SAA levels decreased below ULN only 28 days after first dose. At 72 hours post dose, canakinumab 150mg group was 3.2 (95% CI, 1.27-7.89) times more likely to have less joint tenderness and 2.7 (95% CI, 1.09-6.5) times more likely to have less joint swelling than TA group (p<0.05). At 72 hours post dose, erythema disappeared in 74.1% of patients receiving canakinumab150mg and 69.6% of patients receiving TA. At 7 days post dose, erythema was absent in 96.3% of canakinumab 150mg treated patients vs. 83.9% of patients receiving TA. The overall incidence of AEs was similar for canakinumab (41%) and triamcinolone acetonide (42%). Serious AEs (canakinumab treatment groups n¼4, TA n¼1) were not considered treatment-related by investigators. No discontinuationsdue to AEs occurred.Conclusions : Canakinumab 150mg provided superior pain relief compared to TA for acute flares in difficult-to-treat gouty arthritis patients. Canakinumab provided rapid normalization of markers of inflammation accompanied by reduction of clinical signs and symptoms of inflammation.Disclosure statement : U.A., V.M., D.R. and P.S. are shareholders and employees of Novartis Pharma AG. A.P. has received research support from Novartis Pharma AG. N.S. has received research support from and acts as a consultant for Novartis Pharmaceuticals Corporation, has served on advisory boards for Novartis, Takeda, Savient, URL Pharma and Enzyme Rx, and is/has been a member of a speakers' bureau for Takeda. A.S. has received consultancy fees from Novartis Pharma AG, Abbott, Wyeth, UCB, Roche, MSD, Pfizer, Essex and Bristol-Myers Squibb. All other authors have declared no conflicts of interest.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The major problems associated with the use of corticosteroids for the treatment of ocular diseases are their poor intraocular penetration to the posterior segment when administered locally and their secondary side effects when given systemically. To circumvent these problems more efficient methods and techniques of local delivery are being developed. The purposes of this study were: (1) to investigate the pharmacokinetics of intraocular penetration of hemisuccinate methyl prednisolone (HMP) after its delivery using the transscleral Coulomb controlled iontophoresis (CCI) system applied to the eye or after intravenous (i.v.) injection in the rabbit, (2) to test the safety of the CCI system for the treated eyes and (3) to compare the pharmacokinetic profiles of HMP intraocular distribution after CCI delivery to i.v. injection. For each parameter evaluated, six rabbit eyes were used. For the CCI system, two concentrations of HMP (62.5 and 150mg ml(-1)), various intensities of current and duration of treatment were analyzed. In rabbits serving as controls the HMP was infused in the CCI device but without applied electric current. For the i.v. delivery, HMP at 10mg kg(-1)as a 62.5mg ml(-1)solution was used. The rabbits were observed clinically for evidence of ocular toxicity. At various time points after the administration of drug, rabbits were killed and intraocular fluids and tissues were sampled for methylprednisolone (MP) concentrations by high pressure liquid chromatography (HPLC). Histology examinations were performed on six eyes of each group. Among groups that received CCI, the concentrations of MP increased in all ocular tissues and fluids in relation to the intensities of current used (0.4, 1.0 and 2.0mA/0.5cm(2)) and its duration (4 and 10min). Sustained and highest levels of MP were achieved in the choroid and the retina of rabbit eyes treated with the highest current and 10min duration of CCI. No clinical toxicity or histological lesions were observed following CCI. Negligible amounts of MP were found in ocular tissues in the CCI control group without application of current. Compared to i.v. administration, CCI achieved higher and more sustained tissue concentrations with negligible systemic absorption. These data demonstrate that high levels of MP can be safely achieved in intraocular tissues and fluids of the rabbit eye, using CCI. With this system, intraocular tissues levels of MP are higher than those achieved after i.v. injection. Furthermore, if needed, the drug levels achieved with CCI can be modulated as a function of current intensity and duration of treatment. CCI could therefore be used as an alternative method for the delivery of high levels of MP to the intraocular tissues of both the anterior and posterior segments.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This study aimed to assess application of ultrasound (US) combined with microbubbles (MB) to transfect the ciliary muscle of rat eyes. Reporter DNA plasmids encoding for Gaussia luciferase, β-galactosidase or the green fluorescent protein (GFP), alone or mixed with 50% Artison MB, were injected into the ciliary muscle, with or without US exposure (US set at 1 MHz, 2 W/cm(2), 50% duty cycle for 2 min). Luciferase activity was measured in ocular fluids at 7 and 30 days after sonoporation. At 1 week, the US+MB treatment showed a significant increase in luminescence compared with control eyes, injected with plasmid only, with or without MB (×2.6), and, reporter proteins were localized in the ciliary muscle by histochemical analysis. At 1 month, a significant decrease in luciferase activity was observed in all groups. A rise in lens and ciliary muscle temperature was measured during the procedure but did not result in any observable or microscopic damages at 1 and 8 days. The feasibility to transfer gene into the ciliary muscle by US and MB suggests that sonoporation may allow intraocular production of proteins for the treatment of inflammatory, angiogenic and/or degenerative retinal diseases.

Relevância:

20.00% 20.00%

Publicador:

Relevância:

20.00% 20.00%

Publicador:

Resumo:

SummaryMulticellular organisms have evolved an immune system in order to cope with the constant threats they are facing. Foreign pathogens or endogenous danger signals released by injured or dying host cells can be readily detected through a set of germline- encoded pattern-recognition receptors. The NOD-like receptors are a cytoplasmic family of pattern-recognition receptors that have recently attracted considerable attention due to their ability to form inflammasomes, which are molecular complexes responsible for the activation of caspase-1 and the subsequent processing of the pro¬inflammatory cytokines IL-IB and 11-18 into their mature, bioactive form.In this study, we describe a novel pro-inflammatory signaling pathway, whereby the endoplasmic reticulum promotes inflammation through activation of the NLRP3 inflammasome. This was shown to be independent of the classical endoplasmic reticulum stress response pathway constituted by the effectors IREla, PERK and ATF6a. In keeping with other known NLRP3 activators, generation of reactive oxygen species and potassium efflux were required. We also provide evidence that calcium signaling is critical to this pathway, and possibly integrates signaling triggered by various NLRP3 inflammasome activators. Moreover, the mitochondrial channel VDAC1 was instrumental in mediating this response. We thus propose that the endoplasmic reticulum acts as an integrator of stress and is able to activate the mitochondria in a calcium-dependent manner in order to promote NLRP3 inflammasome activation in response to a wide range of activators.Given the role played by inflammation in the pathogenesis of atherosclerosis, we decided to investigate a possible role for the NLRP3 inflammasome in the progression of the disease. Using an ApoE mouse model, we find that deficiency in the NLRP3 inflammasome components NLRP3, ASC or Caspase-1 does not impair atherosclerosis progression, nor does it impact plaque stability. While previous studies have clearly shown a role for the interleukin-1 family of ligands in atherosclerosis, our results suggest that its contribution might be more complex than previously appreciated, and further research is thus warranted in this field.RésuméLes organismes multicellulaires ont développé un système immunitaire pour faire face aux menaces qui les entourent. Des pathogènes étrangers ou des signaux de danger relâchés par des cellules de l'hôte en détresse peuvent être rapidement détectés via un assemblage de récepteurs spécifiques qui sont présents dès la naissance. Certains membres de la famille de récepteurs NOD ont récemment attiré beaucoup d'attention au vu de leur capacité à former des inflammasomes, complexes moléculaires responsables de l'activation de la easpase-1 et de la maturation des cytokines pro-inflammatoires IL- 1β et IL-18 en leur forme bioactive.Dans cette étude, nous décrivons une nouvelle voie de signalisation pro-inflammatoire, par laquelle le réticulum endoplasmique induit l'inflammation via l'activation de l'inflammasome NLRP3. Cette voie est indépendante de la voie classique de réponse au stress du réticulum endoplasmique, qui comprend les effecteurs IRE1, PERK et ATF6. Comme pour d'autres activateurs de NLRP3, la génération de radicaux libres d'oxygène ainsi que Γ efflux de potassium sont requis. Nous montrons également que le calcium joue un rôle critique dans cette voie, et intègre possiblement la signalisation provoquée par divers activateurs de l'inflammasome NLRP3. De plus, le canal mitochondrial VDAC1 est essentiel dans cette réponse. Nous proposons donc que le réticulum endoplasmique agit comme un intégrateur de stress, activant la mitochondrie d'une façon calcium-dépendante pour promouvoir l'activation de l'inflammasome NLRP3 en réponse à divers activateurs.Au vu du rôle joué par l'inflammation dans la pathogenèse de l'athérosclérose, nous avons étudié un possible rôle pour l'inflammasome NLRP3 dans la progression de la maladie. Dans un modèle de souris ApoE, l'absence des composants de l'inflammasome NLRP3 que sont NLRP3, ASC et Caspase-1 n'influence pas la progression des plaques ni leur stabilité. Alors que d'autres études ont démontré un rôle pour les membres de la famille de l'interleukine-1 dans l'athérosclérose, nos résultats suggèrent que leur contribution pourrait être plus complexe que précédemment apprécié, et d'autres recherches dans ce domaine sont donc nécessaires.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Wound healing proceeds by the concerted action of a variety of signals that have been well identified. However, the mechanisms integrating them and coordinating their effects are poorly known. Herein, we reveal how PPARbeta/delta (PPAR: peroxisome proliferator-activated receptor) follows a balanced pattern of expression controlled by a crosstalk between inflammatory cytokines and TGF-beta1. Whereas conditions that mimic the initial inflammatory events stimulate PPARbeta/delta expression, TGF-beta1/Smad3 suppresses this inflammation-induced PPARbeta/delta transcription, as seen in the late re-epithelialization/remodeling events. This TGF-beta1/Smad3 action involves an inhibitory effect on AP-1 activity and DNA binding that results in an inhibition of the AP-1-driven induction of the PPARbeta/delta promoter. As expected from these observations, wound biopsies from Smad3-null mice showed sustained PPARbeta expression as compared to those of their wild-type littermates. Together, these findings suggest a mechanism for setting the necessary balance between inflammatory signals, which trigger PPARbeta/delta expression, and TGF-beta1/Smad3 that governs the timely decrease of this expression as wound healing proceeds to completion.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Cyclosporine A is a poorly water-soluble, immunosuppressive drug used to treat a variety of ocular diseases. Its limited solubility makes challenging the development of a cyclosporine A-based eye drop for ocular topical application. Based on the prodrug strategy, the practically insoluble cyclosporine A was converted into a freely soluble prodrug. Such a water-soluble prodrug made it possible to develop water-based concentrated eye drops. The prodrug formulations were tested for their ex vivo permeation and in vivo distribution at three concentrations (equivalent to 0.05%, 0.50% and 2.00% w/v cyclosporine A). The ex vivo permeation experiments were performed on corneal and conjunctival epithelia. The in vivo distribution evaluated the total cyclosporine A present in the ocular structures as well as in serum, spleen and cervical lymphatic ganglions. Each prodrug formulation was compared to conventionally used cyclosporine A eye drops at an equivalent concentration. The experimental results showed that the tested eye drops behaved differently. The prodrug formulation was characterized by the following: i) preferential conjunctival penetration, ii) an interesting capacity to create large tissue deposits and iii) a lower risk of systemic complications and immunosuppression. The prodrug aqueous eye drop was demonstrated to be a patient-friendly option for the treatment of ocular diseases requiring high ocular levels of cyclosporine A, pushing the boundaries of the current therapeutic arsenal.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In normal retinas, amyloid-β (Aβ) accumulates in the subretinal space, at the interface of the retinal pigment epithelium, and the photoreceptor outer segments. However, the molecular and cellular effects of subretinal Aβ remain inadequately elucidated. We previously showed that subretinal injection of Aβ(1-42) induces retinal inflammation, followed by photoreceptor cell death. The retinal Müller glial (RMG) cells, which are the principal retinal glial cells, are metabolically coupled to photoreceptors. Their role in the maintenance of retinal water/potassium and glutamate homeostasis makes them important players in photoreceptor survival. This study investigated the effects of subretinal Aβ(1-42) on RMG cells and of Aβ(1-42)-induced inflammation on retinal homeostasis. RMG cell gliosis (upregulation of GFAP, vimentin, and nestin) on day 1 postinjection and a proinflammatory phenotype were the first signs of retinal alteration induced by Aβ(1-42). On day 3, we detected modifications in the protein expression patterns of cyclooxygenase 2 (COX-2), glutamine synthetase (GS), Kir4.1 [the inwardly rectifying potassium (Kir) channel], and aquaporin (AQP)-4 water channels in RMG cells and of the photoreceptor-associated AQP-1. The integrity of the blood-retina barrier was compromised and retinal edema developed. Aβ(1-42) induced endoplasmic reticulum stress associated with sustained upregulation of the proapoptotic factors of the unfolded protein response and persistent photoreceptor apoptosis. Indomethacin treatment decreased inflammation and reversed the Aβ(1-42)-induced gliosis and modifications in the expression patterns of COX-2, Kir4.1, and AQP-1, but not of AQP-4 or GS. Nor did it improve edema. Our study pinpoints the adaptive response to Aβ of specific RMG cell functions.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Sterile cell death mediated inflammation is linked to several pathological disorders and involves danger recognition of intracellular molecules released by necrotic cells that activate different groups of innate pattern recognition receptors. Toll-like receptors directly interact with their extrinsic or intrinsic agonists and induce multiple proinflammatory mediators. In contrast, the NLRP3 inflammasome is rather thought to represent a downstream element integrating various indirect stimuli into proteolytic cleavage of interleukin (IL)-1β and IL-18. Here, we report that histones released from necrotic cells induce IL-1β secretion in an NLRP3-ASC-caspase-1-dependent manner. Genetic deletion of NLRP3 in mice significantly attenuated histone-induced IL-1β production and neutrophil recruitment. Furthermore, necrotic cells induced neutrophil recruitment, which was significantly reduced by histone-neutralizing antibodies or depleting extracellular histones via enzymatic degradation. These results identify cytosolic uptake of necrotic cell-derived histones as a triggering mechanism of sterile inflammation, which involves NLRP3 inflammasome activation and IL-1β secretion via oxidative stress.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background and objectives: Interleukin-18 (IL-18) is a pleiotropic cytokine involved in rheumatoid arthritis (RA) pathogenesis. This studywas carried out to evaluate the efficicacy of interleukin-18 binding protein (IL-18BP) gene therapy in the rat adjuvant-induced arthritis (AIA) model and to decipher the mechanisms by which IL-18BP delivery lessens bone destruction. Materials and methods: Arthritis was induced in female Lewis rat by Mycobacterium butyricum and the mRNA expression of IL-18 and IL-18BP was determined in the joints. In a preventative study, rats were divided into an adenovirus producing IL-18BP-Fc (AdmIL-18BP-Fc) group (n=8) and an adenovirus producing green fluorescent protein (AdGFP) group (n=7). On day 8 after AIA induction, adenoviruses were injected. Clinical parameters were assessed. At day 18, during maximal arthritis, the rats were euthanized, ankles were collected, and X-rays were performed. mRNA and protein were extracted from joints for analyses by qRT-PCR, multiplex, Western blot, and zymography. Results: We observed a decrease in the [IL-18BP/IL-18] ratio from day 7 to day 45. Administration of AdmIL-18BPd-Fc decreased clinical parameters and prevented bone and joint destruction compared to AdGFP administration. IL-18BP delivery reduced the metalloproteinase 9 (MMP-9) levels by 33% (at protein level (Fig. 1B) and functional level (Fig. 1C) and the tartrate-resistant acid phosphatase (TRAP) level by 44% (Fig. 1D) in the joint homogenates from AdmIL-18BPd-Fc compared to AdGFP treated rats.However, no variationwas observed forMMP-2 at the protein level (Fig.1A) and functional level (Fig. 1C). Conclusions: In rat AIA, a decrease in the [IL-18BP/ IL-18] ratio was observed. IL-18BP delivery prevented joint and bone destruction by downregulating MMP-9 and TRAP, suggesting a potential benefit of a similar therapy in RA.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Purpose: To investigate the effect of the first and repeated intravitreal injections of ranibizumab (1.25mg; 0.05ml) on retrobulbar blood flow velocities in patients with wet age-related macular degeneration (AMD). Methods: This prospective non randomized study included twenty consecutive AMD patients. Time- averaged mean blood flow velocities (BFVs) in the central retinal, temporal posterior ciliary and ophthalmic arteries (CRA, TPCA and OA) were measured by ultrasound imaging before, 2 days and 3 weeks after the first injection of ranibizumab, then 6 months after supplemental monthly injections if required. At each visit, complete ophthalmological examination was performed, including best corrected visual acuity measurement according to ETDRS protocol and OCT. Results: In the treated eyes, ranibizumab injection was followed by a significant improvement in visual acuity (from 44.4 ± 21.7, to 50.9±25.9 (p<0.01) at month 6, and a decrease in mean central macular thickness from 377±115 to 267 ± 74 µm (p<0.001) at month 6. At day 2 mean BFVs decreased by 16% in the CRA and by 20% in TPCA (p<0.001, both), then remained stable. Mean BFVs did not change in OA at the day 2 but decreased at week 3 by 18% (p<0.001). Supplemental injections did not lead to additional effects at month 6. No effect was tabulated in the fellow eye. Conclusions: We report an early decrease in mean BFV in CRA and TPRA following intravitreal injections of ranibizumab corresponding to vasoconstrictive effect of this drug. Decrease in mean BFV in all retrobulbar arteries from the week 3 suggests that ranibizumab proceeds to a local and regional vasoconstrictive and antiangiogenic effects after local diffusion. Thus, ranibizumab could induce an actual hypoperfusion of the treated eye which could correspond to a vascular side effect.