AS1411 Nucleolin-Specific Binding Aptamers Reduce Pathological Angiogenesis through Inhibition of Nucleolin Phosphorylation.

Proliferative retinopathies produces an irreversible type of blindness affecting working age and pediatric population of industrialized countries. Despite the good results of anti-VEGF therapy, intraocular and systemic complications are often associated after its intravitreal use, hence novel therapeutic approaches are needed. The aim of the present study is to test the effect of the AS1411, an antiangiogenic nucleolin-binding aptamer, using in vivo, ex vivo and in vitro models of angiogenesis and propose a mechanistic insight. Our results showed that AS1411 significantly inhibited retinal neovascularization in the oxygen induced retinopathy (OIR) in vivo model, as well as inhibited branch formation in the rat aortic ex vivo assay, and, significantly reduced proliferation, cell migration and tube formation in the HUVEC in vitro model. Importantly, phosphorylated NCL protein was significantly abolished in HUVEC in the presence of AS1411 without affecting NFκB phosphorylation and -21 and 221-angiomiRs, suggesting that the antiangiogenic properties of this molecule are partially mediated by a down regulation in NCL phosphorylation. In sum, this new research further supports the NCL role in the molecular etiology of pathological angiogenesis and identifies AS1411 as a novel anti-angiogenic treatment.

Future Perspectives of Therapeutic, Diagnostic and Prognostic Aptamers in Eye Pathological Angiogenesis.

Aptamers are single-stranded DNA or RNA oligonucleotides that are currently used in clinical trials due to their selectivity and specificity to bind small molecules such as proteins, peptides, viral particles, vitamins, metal ions and even whole cells. Aptamers are highly specific to their targets, they are smaller than antibodies and fragment antibodies, they can be easily conjugated to multiple surfaces and ions and controllable post-production modifications can be performed. Aptamers have been therapeutically used for age-related macular degeneration, cancer, thrombosis and inflammatory diseases. The aim of this review is to highlight the therapeutic, diagnostic and prognostic possibilities associated with aptamers, focusing on eye pathological angiogenesis.

Corneal neovascularization is inhibited with nucleolin-binding aptamer, AS1411.

Corneal neovascularization (CNV) is a common sight-threatening pathology that can be induced by a variety of inflammatory and angiogenic stimuli. Current CNV treatments include anti-inflammatory drugs and antibody-based inhibitors of vascular endothelial growth factor (VEGF). However, these are not always effective and novel therapeutic approaches are needed. Previous work has indicated a role for nucleolin (NCL) in VEGF-mediated neoangiogenesis in a suture-induced CNV model. The major goal for this current study is to test the effect of AS1411, a NCL-binding DNA aptamer that has reached human clinical trials, on neovascularization in a murine model of VEGF-mediated CNV. Our results show that topical administration of AS1411 can significantly inhibit corneal neovascularization in this model. Mechanistic studies indicate that AS1411 reduces the VEGF-stimulated proliferation, migration, and tube formation of primary cells obtained from human limbus stroma (HLSC). AS1411 treatment also significantly reduced VEGF-stimulated induction of miR-21 and miR-221 in HLSC, suggesting a role for these pro-angiogenic miRNAs in mediating the effects of AS1411 in this system. In sum, this new research further supports a role for NCL in the molecular etiology of CNV and identifies AS1411 as a potential anti-angiogenic CNV treatment that works by a novel mechanism of action.

Arsenic impairs GLUT1 trafficking through the inhibition of the calpain system in lymphocytes.

Exposure to arsenic is associated with increased risk of developing insulin resistance and type 2 diabetes. The proteases calpain-1 (CAPN1), calpain-2 (CAPN2) and calpain-10 (CAPN10) and their endogenous inhibitor calpastatin (CAST) regulate glucose uptake in skeletal muscle and adipocytes. We investigated whether arsenic disrupts GLUT1 trafficking and function through calpain inhibition, using lymphocytes as a cell model. Lymphocytes from healthy subjects were treated with 0.1 or 1 µM of sodium arsenite for 72 h and challenged with 3.9 or 11.1 mM of glucose. Our results showed that arsenite inhibited GLUT1 trafficking, glucose uptake, and calpain activity in the presence of 11.1 mM of glucose. These correlated with a decrease in the autolytical fragment of 50 kDa of CAPN1 and increased levels of CAST, but there were no changes in CAPN2 and CAPN10. We used a cell-free system to evaluate the effect of arsenite over CAPN1, finding that arsenite induced CAPN1 autolysis. To confirm that calpains are involved in GLUT1 trafficking and glucose uptake in lymphocytes, we generated stable CAPN1 or CAPN10 knockdowns in Jurkat cells using short hairpin RNA (shRNA). CAPN1 knockdown induced glucose uptake, while CAPN10 knockdown diminished glucose uptake, which correlated with a significant reduction of calpain activity after the pulse with 11.1 mM of glucose. These data showed that CAPN10 was responsible for the induction of calpain activity after the challenge with 11.1 mM of glucose and that CAPN1 and CAPN10 regulate glucose uptake in lymphocytes. Altogether, our results suggest that arsenite impairs GLUT1 trafficking and function through calpain dysregulation.

Differential Expression of IL-36 Family Members and IL-38 by Immune and Nonimmune Cells in Patients with Active Inflammatory Bowel Disease.

IL-1 family includes IL-38 (IL-1F10) and the subfamily of IL-36 and is the central mediators of inflammatory diseases, including pustular psoriasis, atopic dermatitis, rheumatoid arthritis, and gut inflammation. The purpose of the study was to evaluate on tissue of the patients with inflammatory bowel disease (IBD), the IL-36α, IL-36ß, IL-36γ, IL-36Ra, and IL-38 gene and cell expression and its correlation with clinical activity. Patients and Methods. A cross-sectional and comparative study was performed. Seventy patients with IBD and 30 noninflamed non-IBD controls were enrolled. Gene expression was measured by RT-PCR. Protein expression was detected by double-staining immunohistochemistry. Results. The mRNA expression of IL-36 family members but not IL-38 was increased in colonic mucosa from patients with active ulcerative colitis versus Crohn's disease group and noninflammatory control group (P<0.05). However, only gene expression of IL-38 was increased in tissue from patients with inactive ulcerative colitis versus active disease and control group (P<0.005). Conversely, gene expression of IL-36Ra was significantly higher in colonic tissue from patients with active versus inactive ulcerative colitis and noninflamed control group (P<0.05). A differential protein overexpression of IL-36α, IL-36ß, IL-36γ, IL-36Ra, and IL-38 by intestinal epithelial cells, macrophages, CD8+ T cells, and/or versus dendritic cells (pDCs) was found in patients with active inflammatory bowel disease compared with noninflamed controls. Conclusion. IL-38 and IL-36 family members' expression was increased by immune and nonimmune cells in patients with active inflammatory bowel disease. These cytokines and IL-36Ra might represent novel therapeutic targets in patients with gut inflammation.