Phosphorylation of STAT3 and ERBB2 mediates hypoxia‑induced VEGF release in ARPE‑19 cells

Targeting the VEGFR2 signaling pathway for angiogenesis and fibrosis regulation in neovascular age-related macular degeneration

Neovascular age-related macular degeneration (nAMD) is characterized by abnormal blood vessel growth from the choroid, leading to complications and eventual blindness. Despite anti-VEGF therapy, subretinal fibrosis remains a major concern, as VEGF/VEGF receptor-2 (VEGFR2) signaling can contribute to both angiogenesis and fibrosis. For the identification of the aqueous humor proteome, we performed liquid chromatography with tandem mass spectrometry analysis. To investigate the potential therapeutic effects of targeting the VEGF signaling pathway using apatinib, a highly selective VEGFR2 tyrosine kinase inhibitor, this study employed in vitro (THP-1 conditioned media-treated ARPE-19 cells) and in vivo (laser-induced choroidal neovascularization mouse) models of nAMD. This study revealed elevated VEGFR2 protein levels in the aqueous humor of nAMD patients, suggesting a potential target to mitigate neovascularization and fibrosis in nAMD. Apatinib effectively reduced VEGFA and αSMA levels in both in vitro and in vivo models. Moreover, apatinib showed improvement in laser-induced subretinal hyper-reflective lesions. The action mechanism was linked to the inhibition of VEGFR2 activation, leading to the suppression of both angiogenesis and fibrosis through the downregulation of STAT3 phosphorylation. Therefore, the VEGFR2 signaling pathway appears to play a central role in the development of nAMD by regulating both angiogenesis and fibrosis.

The Essential Role of Angiogenesis in Adenosine 2A Receptor Deficiency-mediated Impairment of Wound Healing Involving c-Ski via the ERK/CREB Pathways

Adenosine receptor-mediated signaling, especially adenosine A2A receptor (A2AR) signaling, has been implicated in wound healing. However, the role of endothelial cells (ECs) in A2AR-mediated wound healing and the mechanism underlying this effect are still unclear. Here, we showed that the expression of A2AR substantially increased after wounding and was especially prominent in granulation tissue. The delaying effects of A2AR knockout (KO) on wound healing are due mainly to the effect of A2AR on endothelial cells, as shown with A2AR-KO and EC-A2AR-KO mice. Moreover, the expression of c-Ski, which is especially prominent in CD31-positive cells in granulation tissue, increased after wounding and was decreased by both EC-A2AR KO and A2AR KO. In human microvascular ECs (HMECs), A2AR activation induced EC proliferation, migration, tubule formation and c-Ski expression, whereas c-Ski depletion by RNAi abolished these effects. Mechanistically, A2AR activation promotes the expression of c-Ski through an ERK/CREB-dependent pathway. Thus, A2AR-mediated angiogenesis plays a critical role in wound healing, and c-Ski is involved mainly in the regulation of angiogenesis by A2AR via the ERK/CREB pathway. These findings identify A2AR as a therapeutic target in wound repair and other angiogenesis-dependent tissue repair processes.

An inflammatory Signature of Glucose Impairment in Cystic Fibrosis

Objective and Design

Cystic fibrosis-related diabetes (CFRD) is a severe complication associated with increased morbidity and mortality in cystic fibrosis (CF) patients. Extensive inflammatory state in CF leads to pancreas damage and insulin resistance with consequent altered glucose tolerance and CFRD development. The aim of the present study was to identify circulating levels of inflammatory markers specifically associated with impaired glucose tolerance (IGT) and overt CFRD in a sample of young adults with CF.

Materials and Methods

Sixty-four CF outpatients, without evident active pulmonary exacerbation, infectious and autoimmune diseases, were enrolled in the study and the levels of 45 inflammatory serum mediators were measured through x magnetic bead panel multiplex technology.

Results

Serum levels of PDGF-AA, CCL20/MIP3α, IFNα, CCL11/eotaxin, CXCL1/GROα, GMCSF, B7H1/PDL1, IL13, IL7, VEGF, and TGFα were all significantly (p<0.05) elevated in patients according to glycemic status and directly correlated with glycated hemoglobin and C-reactive protein levels.

Conclusion

Our findings suggest that increased levels of specific circulating inflammatory mediators are directly associated with impaired glucose tolerance in CF patients, thus, potentially implicating them in CFRD pathogenesis and warranting larger longitudinal studies to validate their monitoring as predictor of CFRD onset.

Molecular Features of Classic Retinal Drugs, Retinal Therapeutic Targets and Emerging Treatments

The management of exudative retinal diseases underwent a revolution due to the introduction of intravitreal treatments. There are two main classes of intravitreal drugs, namely anti-vascular endothelial growth factors (anti-VEGF) and corticosteroids molecules. The clinical course and the outcome of retinal diseases radically changed thanks to the efficacy of these molecules in determining the regression of the exudation and the restoration of the macular profile. In this review, we described the molecular features of classic retinal drugs, highlighting the main therapeutic targets, and we provided an overview of new emerging molecules. We performed a systematic review of the current literature available in the MEDLINE library, focusing on current intravitreal molecules and on new emerging therapies. The anti-VEGF molecules include Bevacizumab, Pegaptanib, Ranibizumab, Aflibercept, Conbercept, Brolucizumab, Abicipar-pegol and Faricimab. The corticosteroids approach is mainly based on the employment of triamcinolone acetonide, dexamethasone and fluocinolone acetonide molecules. Many clinical trials and real-life reports demonstrated their efficacy in exudative retinal diseases, highlighting differences in terms of molecular targeting and pharmacologic profiles. Furthermore, several new molecules are currently under investigation. Intravitreal drugs focus their activity on a wide range of therapeutic targets and are safe and efficacy in managing retinal diseases.