Biology subjects

Groen, N.

Publications and source records attributed to Groen, N..

4 recordsLinked to original sources

bioRxiv2023

A Single-Cell RNA-Seq Analysis Unravels The Heterogeniety Of Primary Cultured Human Corneal Endothelial Cells

The primary culture of donor-derived human corneal endothelial cells (CECs) is a promising cell therapy. It confers the potential to treat multiple patients from a single donor, alleviating the global donor shortage. Nevertheless, this approach has limitations preventing its adoption, particularly culture protocols allow limited expansion of CECs and there is a lack of clear parameters to identify therapy-grade CECs. To address this limitation, a better understanding of the molecular changes arising from the primary culture of CECs is required. Using single- cell RNA sequencing on primary cultured CECs, we identify their variable transcriptomic fingerprint at the single cell level, provide a pseudo temporal reconstruction of the changes arising from primary culture, and suggest markers to assess the quality of primary CEC cultures. This research depicts a deep transcriptomic understanding of the cellular heterogeneity arising from the primary expansion of CECs and sets the basis for further improvement of culture protocols and therapies.

cell biology↗

bioRxiv2022

SARS-CoV-2 Omicron efficiently infects human airway, but not alveolar epithelium

In late 2021, the highly mutated SARS-CoV-2 Omicron variant emerged, raising concerns about its potential extensive immune evasion, increased transmissibility and pathogenicity. Here, we used organoids of the human airways and alveoli to investigate Omicrons fitness and replicative potential in comparison with earlier SARS-CoV-2 variants. We report that Omicron replicates more rapidly in the airways and has an increased fitness compared to the early 614G variant and Delta. In contrast, Omicron did not replicate productively in human alveolar type 2 cells. Mechanistically, we show that Omicron does not efficiently use TMPRSS2 for entry or spread through cell-cell fusion. Altogether, our data show that Omicron has an altered tropism and protease usage, potentially explaining its higher transmissibility and decreased pathogenicity.

microbiology↗

bioRxiv2021

A single cell transcriptome atlas reveals the heterogeneity of the healthy human cornea and identifies novel markers of the corneal limbus and stroma

The cornea is the clear window that lets light into the eye. It is composed of five layers: epithelium, Bowmans layer, stroma, Descemets membrane and endothelium. The maintenance of its structure and transparency are determined by the functions of the different cell types populating each layer. Attempts to regenerate corneal tissue and understand disease conditions requires knowledge of how cell profiles vary across this heterogeneous tissue. We performed a single cell transcriptomic profiling of 19,472 cells isolated from eight healthy donor corneas. Our analysis delineates the heterogeneity of the corneal layers by identifying cell populations and revealing cell states that contribute in preserving corneal homeostasis. We identified that the expression of CAV1, CXCL14, HOMER3 and CPVL were exclusive to the corneal epithelial limbal stem cell niche, CKS2, STMN1 and UBE2C were exclusively expressed in highly proliferative transit amplifying cells, and NNMT was exclusively expressed by stromal keratocytes. Overall, this research provides a basis to improve current primary cell expansion protocols, for future profiling of corneal disease states, to help guide pluripotent stem cells into different corneal lineages, and to understand how engineered substrates affect corneal cells to improve regenerative therapies.

cell biology↗

bioRxiv2021

Human organoid systems reveal in vitro correlates of fitness for SARS-CoV-2 B.1.1.7

A new phase of the COVID-19 pandemic has started as several SARS-CoV-2 variants are rapidly emerging globally, raising concerns for increased transmissibility. As animal models and traditional in vitro systems may fail to model key aspects of the SARS-CoV-2 replication cycle, representative in vitro systems to assess variants phenotypically are urgently needed. We found that the British variant (clade B.1.1.7), compared to an ancestral SARS-CoV-2 clade B virus, produced higher levels of infectious virus late in infection and had a higher replicative fitness in human airway, alveolar and intestinal organoid models. Our findings unveil human organoids as powerful tools to phenotype viral variants and suggest extended shedding as a correlate of fitness for SARS-CoV-2. One-Sentence SummaryBritish SARS-CoV-2 variant (clade B.1.1.7) infects organoids for extended time and has a higher fitness in vitro.

microbiology↗