Plasma Extracellular Vesicles from Bronchopulmonary Dysplasia Infants Initiate Inflammation and Abnormal Angiogenesis in Neonatal Murine Retinas

TL;DR

Extracellular vesicles from infants with bronchopulmonary dysplasia cause inflammation and abnormal blood vessel growth in mice retinas, suggesting a link to retinopathy of prematurity.

Contribution

This study identifies extracellular vesicles from BPD infants as a novel contributor to retinal inflammation and abnormal angiogenesis in neonatal models.

Findings

BPD-EVs induce activated retinal microglia and Müller cells in neonatal mice.

BPD-EVs cause abnormal neovascularization in mouse retinas compared to nBPD-EVs.

BPD-EVs have elevated levels of inflammation and angiogenesis-related proteins.

Abstract

What are the main findings?
Adoptive transfer of plasma extracellular vesicles from bronchopulmonary dysplasia infants (BPD-EVs) into neonatal mice on postnatal day 3 (P3) induced activated retinal microglia, Müller cells, and abnormal neovascularization on P17 compared to nBPD-EVs.Proteomics analysis of BPD-EVs and nBPD-EVs revealed that BPD-EVs had significantly elevated levels of inflammation and angiogenesis-related proteins compared to nBPD-EVs.

Adoptive transfer of plasma extracellular vesicles from bronchopulmonary dysplasia infants (BPD-EVs) into neonatal mice on postnatal day 3 (P3) induced activated retinal microglia, Müller cells, and abnormal neovascularization on P17 compared to nBPD-EVs.

Proteomics analysis of BPD-EVs and nBPD-EVs revealed that BPD-EVs had significantly elevated levels of inflammation and angiogenesis-related proteins compared to nBPD-EVs.

What are the implications of the main findings?
Circulating EVs may contribute to retinopathy of prematurity (ROP) development in BPD infants by inducing retinal inflammasome-associated inflammation and abnormal angiogenesis.Inflammation and angiogenesis-related proteins in BPD-EVs may represent novel biomarkers and therapeutic targets for the treatment of ROP.

Circulating EVs may contribute to retinopathy of prematurity (ROP) development in BPD infants by inducing retinal inflammasome-associated inflammation and abnormal angiogenesis.

Inflammation and angiogenesis-related proteins in BPD-EVs may represent novel biomarkers and therapeutic targets for the treatment of ROP.

Purpose: To investigate the mechanisms by which plasma extracellular vesicles (EVs) from preterm infants with bronchopulmonary dysplasia (BPD) elicit inflammation and abnormal angiogenesis in neonatal mouse retinas. Methods: EVs from the plasma of 7-day-old preterm infants, born between 230/7 and 296/7 weeks of gestation, with BPD or without BPD (nBPD) at 36 weeks postmenstrual ages, were adoptively transferred into postnatal day 3 (P3) mice via intravenous retro-orbital sinus injection. Inflammation and pathological neovascularization in neonatal mouse retinas were examined by immunohistochemistry of retinal flat mounts for Allograft Inflammatory Factor 1 (AIF1), CD206, or Glial Fibrillary Acidic Protein (GFAP) and isolectin-B4 (IB4) staining on P17. Retinal inflammation-related transcripts were assessed by qRT-PCR. Proteomic profiles of BPD and nBPD EVs were examined by Liquid Chromatograph Mass Spectrometer/Mass Spectrometer (LC-MS/MS) and Gene Set Enrichment Analysis (GSEA). Results: Adoptively transferred EVs from BPD and nBPD infants crossed the blood–retinal barrier (BRB) in recipient mouse pups. BPD-EVs increased retinal activated microglia, Müller cells, and twisted proliferative neovascularization compared to nBPD-EVs. BPD-EVs also elevated retinal transcripts regulating inflammation and angiogenesis, including NOD-, LRR- and pyrin domain-containing protein 3 (Nlrp3), Apoptosis-associated speck-like protein containing a caspase recruitment domain (Asc), Caspase 3 (Casp3), Caspase 8 (Casp8), Gasdermin D (Gsdmd), Il1β, Il6, Aif1, and Vascular endothelial growth factor (Vegf). Proteomics analysis revealed that BPD-EVs had significantly elevated levels of inflammation and angiogenesis-related proteins compared to nBPD-EVs. Conclusions: BPD-EVs promote inflammation and abnormal neovascularization by upregulating genes related to apoptosis and inflammation in neonatal mouse retinas. EV protein profiles suggest that elevated levels of proteins such as Defensin alpha 1B (DEFA1B), Insulin-like growth factor binding protein 2 (IGFBP2), CD5 antigen-like (CD5L), von Willebrand factor (vWF), and Tenascin C (TNC) in BPD-EVs may contribute to the observed inflammation and angiogenesis.

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