Mechanisms of Retinal Damage after Ocular Alkali Burns.

Alkali burns to the eye constitute a leading cause of worldwide blindness. In recent case series, corneal transplantation revealed unexpected damage to the retina and optic nerve in chemically burned eyes. We investigated the physical, biochemical, and immunological components of retinal injury after alkali burn and explored a novel neuroprotective regimen suitable for prompt administration in emergency departments. Thus, in vivo pH, oxygen, and oxidation reduction measurements were performed in the anterior and posterior segment of mouse and rabbit eyes using implantable microsensors. Tissue inflammation was assessed by immunohistochemistry and flow cytometry. The experiments confirmed that the retinal damage is not mediated by direct effect of the alkali, which is effectively buffered by the anterior segment. Rather, pH, oxygen, and oxidation reduction changes were restricted to the cornea and the anterior chamber, where they caused profound uveal inflammation and release of proinflammatory cytokines. The latter rapidly diffuse to the posterior segment, triggering retinal damage. Tumor necrosis factor-α was identified as a key proinflammatory mediator of retinal ganglion cell death. Blockade, by either monoclonal antibody or tumor necrosis factor receptor gene knockout, reduced inflammation and retinal ganglion cell loss. Intraocular pressure elevation was not observed in experimental alkali burns. These findings illuminate the mechanism by which alkali burns cause retinal damage and may have importance in designing therapies for retinal protection.

Role of melatonin, melatonin receptors and STAT3 in the cardioprotective effect of chronic and moderate consumption of red wine.

We have recently discovered that melatonin, given acutely and directly to the isolated heart at the concentration found in wine, confers cardioprotection against ischemia-reperfusion (I/R). However, whether the presence of melatonin in wine contributes to the cardioprotective effect of chronic and moderate consumption of wine and its signalling mechanisms of protection are unknown. We therefore used both in vivo and in vitro models of I/R to investigate whether the presence of melatonin in red wine may contribute to the cardioprotective effect of chronic and moderate consumption of red wine. Wistar rats and C57black6 mice (WT) received drinking water supplemented daily with a moderate amount of red wine or melatonin given at the concentration found in the red wine. Rats were also pretreated with luzindole, a specific inhibitor of melatonin receptors 1 and 2 (2.3 mg/kg/day, intraperitoneally) or prazosin, a specific inhibitor of melatonin receptor type 3 (2.5 mg/kg/day, intraperitoneally). After 14 days, hearts were subjected to I/R in vivo or ex vivo. Red wine reduced the infarct size in both rats and WT mice (p < 0.001). Luzindole did not affect wine-induced cardioprotection, while prazosin reduced the infarct sparing effect of red wine (p < 0.05). Furthermore, red wine or melatonin failed to protect tumor necrosis factor alpha (TNF) receptor 2 knockout or cardiomyocyte specific signal transducer and activator of transcription 3 (STAT3) deficient mice (n.s. vs. control). Our novel findings suggest that the presence of melatonin in red wine contributes to the cardioprotective effect of chronic and moderate consumption of red wine against lethal I/R injuries. This effect is most likely mediated, at least in part, via melatonin receptor 3 and the activation of TNF and STAT3, both key players of the prosurvival and well described SAFE pathway.

Preventive Effect of a Novel Recombinant sTNFRII on Collagen-Induced Arthritis.

We developed a novel trimeric sTNFRII fusion protein, named sTNFRII-gAD, which exhibited a higher in vitro antagonistic efficacy for TNFα in comparison with sTNFRII-Fc. This study aimed to investigate the arthritic protection of sTNFRII-gAD in a rat collagen-induced arthritis (CIA). The rats were injected intradermally with collagen type II at days 0 and 7. Three days after the second injection (day 10), the rats were intraperitoneally given sTNFRII-gAD or sTNFRII-Fc, or PBS. Effects of treatments were examined with respect of CIA incidence, severity and pathological changes. Serum TNFα, IL-17A and regulatory T cell (Treg) in periphery were determined at days 10 and 16, respectively. Our results showed that sTNFRIIgAD significantly reduced CIA incidence and severity (p < 0.05); meanwhile it led to a dramatic improvement in cartilage and bone damage. Moreover, the increase in serum anti-CII and IL-17A, and the reduction in Treg population were inhibited (p < 0.05) by sTNFRII-gAD or sTNFRII-Fc. Serum TNFα was found to be accumulated in the groups treated with sTNFRII-gAD or sTNFRII-Fc compared with the group treated with PBS (p < 0.05). It is noteworthy that sTNFRII-gAD displayed a better efficacy than sTNFRII-Fc in CIA incidence, pathological changes in cartilage and the elevation of anti-CII antibody, indicating that sTNFRII-gAD is potentially a more efficacious anti-TNFα agent for rheumatoid arthritis.

Polyostotic osteolysis and hypophosphatemic rickets with elevated serum fibroblast growth factor 23: A case report.

We report on a boy who presented with hypophosphatemic rickets with elevated serum fibroblast growth factor 23 (FGF23) and polyostotic osteolytic lesions at age 2 years. Tumor-induced hypophosphatemic rickets was suspected; however, bone biopsy for osteolytic changes revealed no tumorous change, except for irregularly dilated vessels associated with osteoclasts and fibrous proliferation. Venous sampling failed to point to FGF23-producing foci. After alfacalcidol and phosphate supplementation, the rachitic skeletal changes improved, but FGF23 increased and new osteolytic lesions developed. Serum levels of neopterin and a few cytokines, including plasma transforming growth factor-ß and soluble tumor necrosis factor receptor type II, were elevated. At age 4 years, high doses of phosphate resulted in increased serum phosphate levels, decreased neopterin and cytokines, decreased FGF23, and stabilization of osteolysis. We excluded germline mutations in PHEX, FGF23, DMP1, and ENPP1 (genes for hereditary hypophosphatemic rickets) and somatic mutations in the GNAS and HRAS/KRAS (the disease-causing genes for McCune-Albright syndrome and linear nevus sebaceous syndrome, respectively). We could not perform octreotide scintigraphy or fluorodeoxyglucose-positron emission tomography, and thus could not completely exclude occult FGF23-producing tumors. However, considering the course of the disease, it is intriguing to assume that dysregulation of osteoclast-macrophage lineage may have induced increased neopterin levels, increased cytokine levels, osteolytic process, and possibly FGF23 overproduction.

The TNFRSF1B rs1061622 polymorphism (p.M196R) is associated with biological drug outcome in Psoriasis patients.

Genetic factors are involved not only in the overall risk of suffering psoriasis, but also in their clinical characteristics and eventually in drug outcome. Biological therapies have dramatically improved the prognosis of Psoriasis. However, these treatments are very expensive and patients often exhibit a heterogeneous response that could be partially attributed to their genetic background. Thus, the research for genetic markers in psoriatic patients that could predict a poor response to biological therapies is an important issue. Our aim was to evaluate the effect of DNA variants at the "TNFα pathway" that could affect the risk of developing Psoriasis or the response to biological therapies among these patients. The genetic association study included a total of 518 Psoriatic patients and 480 healthy controls. Ninety of these patients received biological treatment and based on the change in the PASI score after 24 weeks were classified as good (PASI score ≥75%), intermediate (PASI 50-75), and non-responders (PASI <50). Next generation sequencing (NGS) with semiconductor-array technology was used to identify the nucleotide variants in the TNF α, TNFRSF1A and TNFRSF1B, and we only found three missense amino acid changes, all in TNFRSF1B. Interestingly, we found a significantly higher frequency of rs1061622 G carriers among CW6-positive patients (p = 0.004; OR = 1.69, 95% CI = 1.18-2.41). Allele G (p.196R) carriers were significantly more frequent in the non-responder group (56%) (p = 0.05). In conclusion, we report a significant association between the TNFRSF1B p.M196R variant and the risk for psoriasis and the response to treatment with anti-TNF or anti-Il-12/Il-23. The genotyping of this polymorphism could help to optimize the treatment by identifying patients with a likely poor response to biological drugs.

Selective targeted delivery of the TNF-alpha receptor p75 and uteroglobin to the vasculature of inflamed tissues: a preliminary report.

BACKGROUND: Ligand-targeted approaches have proven successful in improving the therapeutic index of a number of drugs. We hypothesized that the specific targeting of TNF-alpha antagonists to inflamed tissues could increase drug efficacy and reduce side effects. RESULTS: Using uteroglobin (UG), a potent anti-inflammatory protein, as a scaffold, we prepared a bispecific tetravalent molecule consisting of the extracellular ligand-binding portion of the human TNF-alpha receptor P75 (TNFRII) and the scFv L19. L19 binds to the ED-B containing fibronectin isoform (B-FN), which is expressed only during angiogenesis processes and during tissue remodeling. B-FN has also been demonstrated in the pannus in rheumatoid arthritis. L19-UG-TNFRII is a stable, soluble homodimeric protein that maintains the activities of both moieties: the immuno-reactivity of L19 and the capability of TNFRII to inhibit TNF-alpha. In vivo bio-distribution studies demonstrated that the molecule selectively accumulated on B-FN containing tissues, showing a very fast clearance from the blood but a very long residence time on B-FN containing tissues. Despite the very fast clearance from the blood, this fusion protein was able to significantly improve the severe symptomatology of arthritis in collagen antibody-induced arthritis (CAIA) mouse model. CONCLUSIONS: The recombinant protein described here, able to selectively deliver the TNF-alpha antagonist TNFRII to inflamed tissues, could yield important contributions for the therapy of degenerative inflammatory diseases.

Simple and highly sensitive assay system for TNFR2-mediated soluble- and transmembrane-TNF activity.

Drugs that target tumor necrosis factor-alpha (TNF) are particularly important in the treatment of severe inflammatory progression in rheumatoid arthritis, Crohn's disease and psoriasis. Despite the central role of the TNF/TNF receptor (TNFR) in various disease states, there is a paucity of information concerning TNFR2 signaling. In this study, we have developed a simple and highly sensitive cell-death based assay system for analyzing TNFR2-mediated bioactivity that can be used to screen for TNFR2-selective drugs. Using a lentiviral vector, a chimeric receptor was engineered from the extracellular and transmembrane domain of human TNFR2 and the intracellular domain of mouse Fas and the recombinant protein was then expressed in TNFR1(-/-)R2(-/-) mouse preadipocytes. Our results demonstrate that this chimeric receptor is capable of inducing apoptosis by transmembrane- as well as soluble-TNF stimuli. Moreover, we found that our bioassay based on cell death phenotype had an approximately 80-fold higher sensitivity over existing bioassays. We believe our assay system will be an invaluable research tool for studying TNFR2 and for screening TNFR2-targeted drugs.

[Gene therapy for osteoarticular disorders]. / Application des techniques de thérapie génique aux maladies ostéo-articulaires.

Osteoarticular disorders are the major cause of disability in Europe and North America. It is estimated that rheumatoid arthritis affects 1 % of the population and that more than two third of people over age 55 develop osteoarthritis. Because there are no satisfactory treatments, gene therapy offers a new therapeutic approach. The delivery of cDNA encoding anti-arthritic proteins to articular cells has shown therapeutic efficacy in numerous animal models in vivo. Through the development and the experimental progresses that have been made for both rheumatoid arthritis and osteoarthritis, this review discusses the different gene therapy strategies available today and the safety issues with which they may be associated. Among the different vectors available today, adeno-associated virus seems the best candidate for a direct in vivo gene delivery approach for the treatment of joint disorders.

Inhibition of established collagen-induced arthritis with a tumour necrosis factor-alpha inhibitor expressed from a self-contained doxycycline regulated plasmid.

Tumor necrosis factor (TNF)-alpha is produced by cells of the immune system and is a key mediator in immune and inflammatory reactions. Through interaction with widely expressed receptors (TNF receptor 1 and TNF receptor 2), TNF-alpha is able to orchestrate the expression of a range of downstream proinflammatory molecules. Over the past decade novel biologics that inhibit TNF-alpha have been developed as extremely effective treatments for rheumatoid arthritis. Structurally, these biologics are antibodies, or TNF receptors on an antibody backbone that bind TNF-alpha directly and are delivered to patients by repeated injection. Gene therapy offers an improved approach to delivering biologics as a single administration of their encoding genetic material. In the present study we demonstrate the therapeutic effect of a small molecular weight dimeric TNF receptor 2 (dTNFR) constitutively expressed from plasmid DNA, delivered intramuscularly with electroporation, after disease onset in a collagen-induced arthritis model. Regulated promoters that enable the production of a transgene to be controlled are more suited to the application of gene therapy in the clinic. Regulated expression of dTNFR from the plasmid pGTRTT was also therapeutic in the mouse collagen-induced arthritis model when the inducer doxycycline was also administered, whereas no therapeutic effect was observed in the absence of doxycycline. The therapeutic effect of dTNFR expressed from a constitutive or regulated plasmid was dependent on the degree of disease activity at the time of DNA injection. The observations of this study are considered with regard to the disease model, the magnitude of gene regulation, and the path to clinical application.