Spontaneous Neutrophil Extracellular Traps Release Are Inflammatory Markers Associated with Hyperglycemia and Renal Failure on Diabetic Retinopathy.

Diabetic retinopathy (DR) is the major microvascular complication of diabetes and causes vitreous traction and intraretinal hemorrhages leading to retinal detachment and total blindness. The evolution of diabetes is related to exacerbating inflammation caused by hyperglycemia and activation of inflammatory cells. Neutrophils are cells able to release structures of extracellular DNA and proteolytic enzymes called extracellular traps (NETs), which are associated with the persistence of inflammation in chronic pathologies. The purpose of the study was to determine the usefulness of neutrophil traps as indicators of DR progression in patients with type 2 diabetes (T2DM). We performed a case-control study of seventy-four cases classified into five groups (non-proliferative DR, mild, moderate, severe, and proliferative) and fifteen healthy controls. We found correlations between NETs and a diagnostic time of T2DM (r = 0.42; p < 0.0001), fasting glucose (r = 0.29; p < 0.01), glycated hemoglobin (HbA1c) (r = 0.31; p < 0.01), estimated glomerular filtration rate (eGFR) (r = -0.29; p < 0.01), and plasma osmolarity (r = 0.25; p < 0.01). These results suggest that due to NETs being associated with clinical indicators, such as HbA1c and eGFR, and that NETs are also associated with DR, clinical indicators might be explained in part through an NET-mediated inflammation process.

Seroprevalence of SARS-CoV-2 in Mexican Health Care Workers after Two Years of the Pandemic: The Picture of an Ophthalmic Medical Centre.

OBJECTIVE: In this study, we investigated the impact of the SARS-CoV-2 vaccination on seroprevalence in a cohort of healthcare workers (HCW) at an ophthalmic medical center. METHODS: IgG antibodies against the N, S1, and S2 antigens of SARS-CoV-2 as well as their serum neutralizing activity were determined. RESULTS: In the present study, we observed that 98.4% of HCW were seropositive for S1/S2 proteins of SARS-CoV-2 due to the national vaccination program. Interestingly, 78.4% of the participants had anti-N protein antibodies, suggesting previous COVID-19 infection. We also evaluated the neutralizing antibodies and found that the mean value was high (90.7%). CONCLUSION: These results indicate that our HCWs cohort presented a robust hybrid humoral response owing to the massive national vaccination program and natural infections.

Human Amniotic Membrane Mesenchymal Stem Cell-Synthesized PGE2 Exerts an Immunomodulatory Effect on Neutrophil Extracellular Trap in a PAD-4-Dependent Pathway through EP2 and EP4.

Human amniotic membrane mesenchymal stem cells (hAM-MSC) secrete a myriad of components with immunosuppressive activities. In the present research, we aimed to describe the effect of prostaglandin E2 (PGE2) secreted by hAM-MSCs on neutrophil extracellular trap (NET) release and to characterize the role of its receptors (EP2/EP4) in PAD-4 and NFκB activity in neutrophils. Human peripheral blood neutrophils were ionomycin-stimulated in the presence of hAM-MSC conditioned medium (CM) treated or not with the selective PGE2 inhibitor MF-63, PGE2, EP2/EP4 agonists, and the selective PAD-4 inhibitor GSK-484. NET release, PAD-4, and NFκB activation were analyzed. Ionomycin induced NET release, which was inhibited in the presence of hAM-MSC-CM, while CM from hAM-MSCs treated with MF-63 prevented NET release inhibition. PGE2 and EP2/EP4 agonists, and GSK-484 inhibited NET release. EP2/EP4 agonists and GSK-484 inhibited H3-citrullination but did not affect PAD-4 protein expression. Finally, PGE2 and EP2/EP4 agonists and GSK-484 increased NFκB phosphorylation. Taken together, these results suggest that hAM-MSC exert their immunomodulatory activities through PGE2, inhibiting NET release in a PAD-4-dependent pathway. This research proposes a new mechanism by which hAM-MSC exert their activities when modulating the innate immune response and inhibiting NET release.

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.