👤 Justis P Ehlers

Retinal vein occlusion (RVO) is the second most common retinal vascular disorder. Despite promising advances with anti-VEGF therapy, select patients are unresponsive to therapy. A precision medicine-based approach for therapeutic decision-making based on underlying biomarkers may facilitate treatment based on the underlying pathway. This study aims to identify the baseline and longitudinal cytokine profiles of RVO-related macular oedema and correlating these expression profiles with higher order OCT features using a novel retinal segmentation and feature extraction platform. The IMAGINE study is a post-hoc assessment of aqueous humour cytokines with correlation to higher level analysis of imaging studies. OCT scans underwent machine learning enhanced segmentation of the internal limiting membrane (ILM), ellipsoid zone (EZ) and retinal pigment epithelium (RPE), as well as evaluating volumetric fluid metrics. Samples of aqueous humour were obtained at baseline, as well as months 4 and 9 prior to treatment. These samples were analysed for the expression of multiple cytokines. Patients were divided into Responders and Non-Responders based on OCT profiles. Additionally, patients were categorised as a Rebounder if their CST increased by 50% after initial improvement. Twenty-six eyes were included. The OCT-based response schema identified 21 Responders (81%) and 5 Non-Responders (19%). VEGF levels directly correlated with intraretinal fluid volume and angiogenin was inversely correlated with fluid indices. Multiple cytokines, including ANGPTL4, were directly correlated with ellipsoid zone disruption. The baseline VEGF levels were significantly higher in all responders compared to Non-Responders (p = 0.02). Rebounders tended to have significantly decreased levels of angiogenin and TIMP-1 (p = 0.019, p = 0.015). Cytokine expression was linked to specific OCT features and treatment response in RVO. Identification of an imaging phenotype that could serve as a surrogate for underlying active disease pathways could enhance treatment decision-making and precision medicine. Show less

Various pathways and cytokines are implicated in pathogenesis of diabetic macular edema (DME). Computational imaging biomarkers (CIBs) of vessel tortuosity from ultra-widefield fluorescein angiography (UWFA) and texture patterns from OCT images have been associated with anti-vascular endothelial growth factor (VEGF) therapy treatment response in DME. This analysis was a radiogenomic assessment of the association between underlying cytokines, UWFA, and OCT-based DME CIBs. Biclustering analysis based on UWFA and OCT CIBs to identify a common imaging phenotype across patients with subsequent assessment of underlying cytokine signatures and treatment response attributes. The IMAGINE DME study was a post hoc study of cytokine expressions that included 24 eyes with sufficient baseline aqueous humor samples and an in-depth assessment of the imaging studies obtained during the phase I/II DmeAntiVEgf study (DAVE) that measured different cytokine expressions. A total of 151 graph or morphologic features quantifying leakage shape, size, density, interobject distance, and architecture of leakage spots and 5 vessel tortuosity features were extracted from the baseline UWFA scans, and 494 texture-based radiomics features were extracted from each of the fluid and retinal tissue compartments of OCT images. Biclustering enables simultaneous clustering of patients and features and was used to aggregate patients in terms of their commonality of phenotypes (based on similar imaging attributes) and to identify commonality in terms of cytokine expression and treatment response to anti-VEGF therapy. Identification of eyes with similar imaging phenotypes to evaluate commonalities of patterns and underlying cytokine expression. Strong correlations between VEGF and 7 UWFA leakage morphologic features (Pearson correlation coefficient [PCC], 0.45-0.51; This study identified groups of eyes with similar imaging phenotypes as defined by UWFA and OCT CIBs that demonstrated similar treatment response patterns and cytokine expression, including a strong association between VEGF with UWFA-derived leakage morphologic and vessel tortuosity features. Show less

In primary central nervous system tumours, epithelial-to-mesenchymal transition (EMT) gene expression is associated with increased malignancy. However, it has also been shown that EMT factors in gliomas are almost exclusively expressed by glioma vessel-associated pericytes (GA-Peris). In this study, we aimed to identify the mechanism of EMT in GA-Peris and its impact on angiogenic processes. In glioma patients, vascular density and the expression of the pericytic markers platelet derived growth factor receptor (PDGFR)-β and smooth muscle actin (αSMA) were examined in relation to the expression of the EMT transcription factor SLUG and were correlated with survival of patients with glioblastoma (GBM). Functional mechanisms of SLUG regulation and the effects on primary human brain vascular pericytes (HBVP) were studied in vitro by measuring proliferation, cell motility and growth characteristics. The number of PDGFR-β- and αSMA-positive pericytes did not change with increased malignancy nor showed an association with the survival of GBM patients. However, SLUG-expressing pericytes displayed considerable morphological changes in GBM-associated vessels, and TGF-β induced SLUG upregulation led to enhanced proliferation, motility and altered growth patterns in HBVP. Downregulation of SLUG or addition of a TGF-β antagonising antibody abolished these effects. We provide evidence that in GA-Peris, elevated SLUG expression is mediated by TGF-β, a cytokine secreted by most glioma cells, indicating that the latter actively modulate neovascularisation not only by modulating endothelial cells, but also by influencing pericytes. This process might be responsible for the formation of an unstructured tumour vasculature as well as for the breakdown of the blood-brain barrier in GBM. Show less

Effector functions of IgG Abs are regulated by their Fc N-glycosylation pattern. IgG Fc glycans that lack galactose and terminal sialic acid residues correlate with the severity of inflammatory (auto)immune disorders and have also been linked to protection against viral infection and discussed in the context of vaccine-induced protection. In contrast, sialylated IgG Abs have shown immunosuppressive effects. We sought to investigate IgG glycosylation programming during the germinal center (GC) reaction following immunization of mice with a foreign protein antigen and different adjuvants. Mice were analyzed for GC T-cell, B-cell, and plasma cell responses, as well as for antigen-specific serum IgG subclass titers and Fc glycosylation patterns. Different adjuvants induce distinct IgG This study's findings regarding adjuvant-dependent GC responses and IgG glycosylation programming may aid in the development of novel vaccination strategies to induce IgG Abs with both high affinity and defined Fc glycosylation patterns in the GC. Show less