Molecular and Functional Characterization of Human Intestinal Organoids and Monolayers for Modeling Epithelial Barrier

Patient-derived organoid models can transform drug discovery for inflammatory bowel disease, but differentiation and functional characterization inconsistencies limit that transformation. Jelinsky et al. profiled molecular and cellular features across a range of intestinal organoid models using bulk RNA sequencing, among other technologies, and examined differentiation and establishing a functional epithelial barrier.

A single cell transcriptional roadmap of human pacemaker cell differentiation

Wiesinger et al. combine SORT-seq analysis with trajectory inference to reconstruct lineage decisions of sinoatrial node–like cardiomyocytes (derived from induced pluripotent stem cells). WNT and TGFb signaling seem to play a role in these lineage decisions, the authors find.

Molecular and electrophysiological evaluation of human cardiomyocyte subtypes to facilitate generation of composite cardiac models

The authors directed the differentiation of human induced pluripotent stem cells to three types of heart cell: sinoatrial nodal, atrial and ventricular cardyomyocytes. SORT-seq established that the protocols indeed yielded distinct cell populations in line with expected identities. Such models can progress the use of cardiomyocytes in drug development.

Human regulatory T cells locally differentiate and are functionally heterogeneous within the inflamed arthritic joint

The authors combined SORT-seq and T cell receptor sequencing to investigate the heterogeneity of regulatory T cells (Tregs) derived from synovial fluid of three patients with juvenile idiopathic arthritis. Results indicate Tregs differentiate to classical effector Tregs or GRP56+CD161+CXCL13+ Tregs. They also found novel predicted drivers of local Treg differentiation.

Quality assurance of hematopoietic stem cells by macrophages determines stem cell clonality

Wattrus et al. establish that hematopoietic stem and progenitor cells (HSPC) are quality assured for stress levels during development. Calreticulin is revealed as an “eat-me” molecule that initiates macrophage-HSPC interaction and leads to programmed cell clearance or stem cell expansion. They used SORT-seq to characterize the macrophage and HSPC subpopulations involved.

The whole-cell pertussis vaccine imposes a broad effector B-cell response in mouse heterologous prime-boost settings

The authors compare effector and memory B cells induced by the two classes of pertussis vaccines (whole cell and acellular versions) using SORT-seq among other techniques. They show that a whole-cell pertussis vaccine prime achieves a more potent and broader memory B cell and plasma-cell response.

JAG1-NOTCH4 mechanosensing drives atherosclerosis

Heart attack and stroke can be caused by endothelial cell–triggered atherosclerosis. This paper shows that disturbed blood flow activates the JAG1-NOTCH4 signaling pathway. SORT-seq analysis indicates Jag1 suppresses proliferative endothelial cells, enhancing atherosclerosis susceptibility.

A pendulum of induction between the epiblast and extra-embryonic endoderm supports post-implantation progression

Vrij et al. aim to elucidate the principles of epiblast and extraembryonic endoderm co-development in mice. SORT-seq and immunofluorescence microscopy analysis indicate a process of lineage bifurcation and the two layers sequentially inducing developmental progression in each other.

Molecular signatures and cellular diversity during mouse habenula development

The authors performed SORT-seq on mouse habenular neurons at critical developmental stages, instructed by detailed 3D anatomical data. The data reveal cellular and molecular trajectories during embryonic and postnatal development, leading to different habenular subtypes. Among these, the Cartpt+ neuron subtype was studied in-depth and successfully linked to specific molecular and functional properties.

Single-cell transcriptomics provides insights into hypertrophic cardiomyopathy

Wehrens et al. perform single-cell RNA sequencing on the hearts of patients who suffer from hypertrophic cardiomyopathy (HCM). This reveals cardiomyocyte subpopulations, gene regulatory networks, transcription factors, and hypertrophy-related genes that might be relevant to the pathogenesis of the disease.

Characterization of HIV-1 Infection in Microglia-Containing Human Cerebral Organoids

Gumbs et al. study the molecular mechanisms of HIV entry into central nervous system organoids and identify microglia as the primary target cell. Single-cell RNA sequencing confirmed the presence of microglia, among other cell types, and HIV-entry receptor expression in brain organoids.

Linking the genotypes and phenotypes of cancer cells in heterogenous populations via real-time optical tagging and image analysis

This paper describes how cells can be optically tagged in real-time based on specific functional cell dynamics, such as fast migration or morphological variation. Moreover, it documents how you can combine optical tagging with single-cell RNA sequencing to link the genotypes and phenotypes of heterogenous tumor populations.