Reporter mice for isolating and auditing cell type-specific extracellular vesicles in vivo.

Extracellular vesicles (EVs) are abundant, lipid-enclosed vectors that contain nucleic acids and proteins, they can be secreted from donor cells and freely circulate, and they can be engulfed by recipient cells thus enabling systemic communication between heterotypic cell types. However, genetic tools for labeling, isolating, and auditing cell type-specific EVs in vivo, without prior in vitro manipulation, are lacking. We have used CRISPR-Cas9-mediated genome editing to generate mice bearing a CD63-emGFPloxP/stop/loxP knock-in cassette that enables the specific labeling of circulating CD63+ vesicles from any cell type when crossed with lineage-specific Cre recombinase driver mice. As proof-of-principle, we have crossed these mice with Cdh5-CreERT2 mice to generate CD63emGFP+ vasculature. Using these mice, we show that developing vasculature is marked with emerald GFP (emGFP) following tamoxifen administration to pregnant females. In adult mice, quiescent vasculature and angiogenic vasculature (in tumors) is also marked with emGFP. Moreover, whole plasma-purified EVs contain a subpopulation of emGFP+ vesicles that are derived from the endothelium, co-express additional EV (e.g., CD9 and CD81) and endothelial cell (e.g., CD105) markers, and they harbor specific miRNAs (e.g., miR-126, miR-30c, and miR-125b). This new mouse strain should be a useful genetic tool for generating cell type-specific, CD63+ EVs that freely circulate in serum and can subsequently be isolated and characterized using standard methodologies.

Roles of miR-640 and Zinc Finger Protein 91 (ZFP91) in Angiopoietin-1-Induced In Vitro Angiogenesis.

Angiopoietin-1 (Ang-1) is a ligand of Tie-2 receptors that promotes angiogenesis. It has been established that regulatory loops exist between angiogenic growth factors and distinct pro or anti-angiogenic miRNAs, but the nature and the roles of Ang-1-regulated miRNAs remain unclear. In this study, we assessed the role of miR-640 in Ang-1-induced angiogenesis in human umbilical vein endothelial cells (HUVECs). Exposure to Ang-1 (300 ng/mL) from 6 to 72 h significantly decreased expression of mature miR-640, a response that was mediated by Tie-2 receptors and was also observed in response to Ang-2, the vascular endothelial growth factor, and transforming growth factor ß. Increasing miR-640 levels using a mimic inhibited Ang-1-induced cell migration and capillary-like tube formation whereas inhibition of miR-640 enhanced these responses. Pull down assays of biotinylated miR-640 revealed that miR-640 directly targets Zinc Finger Protein 91 (ZFP91), an atypical E3-ubiquitin ligase. Ang-1 exposure induced ZFP91 expression through down-regulation of miR-640. Silencing of ZFP91 significantly inhibited Ang-1-induced cell migration and tube formation. We conclude that Ang-1 upregulates ZFP91 expression through transcriptional down-regulation of miR-640 and that ZFP91 plays important roles in the promotion of Ang-1-induced endothelial cell migration and differentiation.

PDX-derived organoids model in vivo drug response and secrete biomarkers.

Patient-derived organoid models are proving to be a powerful platform for both basic and translational studies. Here we conduct a methodical analysis of pancreatic ductal adenocarcinoma (PDAC) tumor organoid drug response in paired patient-derived xenograft (PDX) and PDX-derived organoid (PXO) models grown under WNT-free culture conditions. We report a specific relationship between area under the curve value of organoid drug dose response and in vivo tumor growth, irrespective of the drug treatment. In addition, we analyzed the glycome of PDX and PXO models and demonstrate that PXOs recapitulate the in vivo glycan landscape. In addition, we identify a core set of 57 N-glycans detected in all 10 models that represent 50%-94% of the relative abundance of all N-glycans detected in each of the models. Last, we developed a secreted biomarker discovery pipeline using media supernatant of organoid cultures and identified potentially new extracellular vesicle (EV) protein markers. We validated our findings using plasma samples from patients with PDAC, benign gastrointestinal diseases, and chronic pancreatitis and discovered that 4 EV proteins are potential circulating biomarkers for PDAC. Thus, we demonstrate the utility of organoid cultures to not only model in vivo drug responses but also serve as a powerful platform for discovering clinically actionable serologic biomarkers.

Dermatosis pustular subcórnea: experiencia de once años en un centro de referencia nacional. Reporte de casos / Subcorneal pustular dermatosis: Eleven years of experience in a national reference center

Resumen La dermatosis pustular subcórnea es una dermatosis infrecuente y poco conocida. El objetivo de este trabajo es describir la experiencia de los autores en el diagnóstico y tratamiento de un grupo de pacientes colombianos con esta enfermedad. Se presentan seis casos diagnosticados entre los años 2010 y 2021. Todos los afectados tenían lesiones de larga evolución (en promedio 5 años) y las zonas del cuerpo más afectadas fueron el tórax (83 %), las axilas (66 %) y el tercio proximal de las extremidades (50 %). Las lesiones semiológicas más comunes fueron las pústulas (83 %), las pápulas (83 %) y las placas eritematocostrosas con bordes circinados (50 %); las pústulas flácidas típicas solo se observaron en dos casos (33 %). En conclusión, el diagnóstico de la dermatosis pustular subcórnea requiere del reconocimiento de un amplio espectro de manifestaciones clínicas, así como una adecuada correlación clínico-patológica.

Abstract Subcorneal pustular dermatosis is a rare and little known dermatosis. The objective of this paper is to describe the experience of the authors in the diagnosis and treatment of a group of Colombian patients with this disease. Six cases are presented, diagnosed between 2010 and 2021. All of the patients had long-standing lesions (on average 5 years) and the most affected areas were the thorax (83%), the armpits (66%), and the proximal third of the extremities (50%). The most common lesions were pustules (83%), papules (83%), and erythematous-crusted plaques with circinated edges (50%); typical flaccid pustules were only observed in two cases (33%). In conclusion, the timely diagnosis of subcorneal pustular dermatosis requires recognition of a wide spectrum of clinical presentations, as well as adequate clinicopathological correlation.