Project description:Colonic resections were obtained from patients operated for sigmoid colon cancer at Akershus University Hospital (Ahus, 1478 Lørenskog, Norway). The resected colon was immediately examined by an experienced pathologistand macroscopically normal colon, at least 10 cm from the tumor, were placed in vials with RPMI 1640 and put on ice for transport. The study was performed in accordance with the Declaration of Helsinki. Written informed consent was obtained from all participants, and the study was approved by the Regional Committee for Medical Research Ethics (REK, 2018/703, Health Region South-East, Norway). For scRNA-seq, 4 colon specimens from sigmoid or ascending colon were obtained (age 62-78, 3 males). Immunofluorescence stainings were done on samples from 8 patients (age 62-78, 4 males) from ascending, transverse, descending and sigmoid colon. None of the patients had autoimmune, infectious or inflammatory diseases, nor received neoadjuvant chemotherapy or radiation therapy before the operation. All patients were operated following the national guidelines.
Project description:Development of the human intestine is not well understood. Here, we link single-cell RNA sequencing and spatial transcriptomics to characterize intestinal morphogenesis through time. We identify 101 cell states including epithelial and mesenchymal progenitor populations and programs linked to key morphogenetic milestones. We describe principles of crypt-villus axis formation; neural, vascular, mesenchymal morphogenesis, and immune population of the developing gut. We identify the differentiation hierarchies of developing fibroblast and myofibroblast subtypes and describe diverse functions for these including as vascular niche cells. We pinpoint the origins of Peyer's patches and gut-associated lymphoid tissue (GALT) and describe location-specific immune programs. We use our resource to present an unbiased analysis of morphogen gradients that direct sequential waves of cellular differentiation and define cells and locations linked to rare developmental intestinal disorders. We compile a publicly available online resource, spatio-temporal analysis resource of fetal intestinal development (STAR-FINDer), to facilitate further work.
Project description:The therapeutic application of human induced pluripotent stem cells (hiPSCs) for cartilage regeneration is largely hindered by the low yield of chondrocytes accompanied by unpredictable and heterogeneous off-target differentiation of cells during chondrogenesis. Here, we combine bulk RNA sequencing, single cell RNA sequencing, and bioinformatic analyses, including weighted gene co-expression analysis (WGCNA), to investigate the gene regulatory networks regulating hiPSC differentiation under chondrogenic conditions. We identify specific WNTs and MITF as hub genes governing the generation of off-target differentiation into neural cells and melanocytes during hiPSC chondrogenesis. With heterocellular signaling models, we further show that WNT signaling produced by off-target cells is responsible for inducing chondrocyte hypertrophy. By targeting WNTs and MITF, we eliminate these cell lineages, significantly enhancing the yield and homogeneity of hiPSC-derived chondrocytes. Collectively, our findings identify the trajectories and molecular mechanisms governing cell fate decision in hiPSC chondrogenesis, as well as dynamic transcriptome profiles orchestrating chondrocyte proliferation and differentiation.
Project description:Intrathymic differentiation of T lymphocytes begins as early as intrauterine stage, yet the T cell lineage decisions of human fetal thymocytes at different gestational ages are not currently understood. Here, we performed integrative single-cell analyses of thymocytes across gestational ages. We identified conserved candidates underlying the selection of T cell receptor (TCR) lineages in different human fetal stages. The trajectory of early thymocyte commitment during fetal growth was also characterized. Comparisons with mouse data revealed conserved and species-specific transcriptional dynamics of thymocyte proliferation, apoptosis and selection. Genome-wide association study (GWAS) data associated with multiple autoimmune disorders were analyzed to characterize susceptibility genes that are highly expressed at specific stages during fetal thymocyte development. In summary, our integrative map describes previously underappreciated aspects of human thymocyte development, and provides a comprehensive reference for understanding T cell lymphopoiesis in a self-tolerant and functional adaptive immune system.
Project description:Neural crest (NC) cells migrate throughout vertebrate embryos to give rise to a huge variety of cell types, but when and where lineages emerge and their regulation remain unclear. We have performed single-cell RNA sequencing (RNA-seq) of cranial NC cells from the first pharyngeal arch in zebrafish over several stages during migration. Computational analysis combining pseudotime and real-time data reveals that these NC cells first adopt a transitional state, becoming specified mid-migration, with the first lineage decisions being skeletal and pigment, followed by neural and glial progenitors. In addition, by computationally integrating these data with RNA-seq data from a transgenic Wnt reporter line, we identify gene cohorts with similar temporal responses to Wnts during migration and show that one, Atp6ap2, is required for melanocyte differentiation. Together, our results show that cranial NC cell lineages arise progressively and uncover a series of spatially restricted cell interactions likely to regulate such cell-fate decisions.
Project description:Atherosclerosis is the main cause of many cardiovascular and cerebrovascular diseases (CVDs), and gaining a deeper understanding of the intercellular connections and key central genes which mediate formation of atherosclerotic plaques is required. We performed a comprehensive bioinformatics analysis of differential genetic screening, Kyoto Encyclopedia of Genes and Genomes (KEGG) signaling pathway annotation, protein-protein interactions (PPIs), pseudo-timing, intercellular communication, transcription factors on carotid single-cell sequencing data, and aortic bulk transcriptome and metabolomic data. Ten cell types were identified in the data: T cells, monocytes, smooth muscle cells, endothelial cells, B cells, fibroblasts, plasma cells, mast cells, dendritic cells, and natural killer cells. Endothelial, fibroblast, macrophage, and smooth muscle cell subtype differentiation trajectories, interaction networks, and important transcription factors were characterized in detail. Finally, using this information combined with transcriptome and metabolome analyses, we found the key genes and signaling pathways of atherosclerosis, especially the advanced glycation end products and receptor for advanced glycation end products signaling pathway (AGE-RAGE signaling pathway) in diabetic complications, linked the differential metabolites with fibroblasts and atherosclerosis and contributed to it in patients with diabetes. Collectively, this study provides key genes, signaling pathways, cellular communication, and transcription factors among endothelial cells, fibroblasts, macrophages, and smooth muscle cells for the study of atherosclerotic plaques, and provides a basis for the diagnosis and treatment of atherosclerosis-like sclerosis.
Project description:Endometriosis is a common condition in women that causes chronic pain and infertility and is associated with an elevated risk of ovarian cancer. We profiled transcriptomes of >370,000 individual cells from endometriomas (n = 8), endometriosis (n = 28), eutopic endometrium (n = 10), unaffected ovary (n = 4) and endometriosis-free peritoneum (n = 4), generating a cellular atlas of endometrial-type epithelial cells, stromal cells and microenvironmental cell populations across tissue sites. Cellular and molecular signatures of endometrial-type epithelium and stroma differed across tissue types, suggesting a role for cellular restructuring and transcriptional reprogramming in the disease. Epithelium, stroma and proximal mesothelial cells of endometriomas showed dysregulation of pro-inflammatory pathways and upregulation of complement proteins. Somatic ARID1A mutation in epithelial cells was associated with upregulation of pro-angiogenic and pro-lymphangiogenic factors and remodeling of the endothelial cell compartment, with enrichment of lymphatic endothelial cells. Finally, signatures of ciliated epithelial cells were enriched in ovarian cancers, reinforcing epidemiologic associations between these two diseases.
Project description:Mesenchymal stem cells (MSCs) are a population of multipotent cells with a superior ability to promote tissue repair by regulating regeneration and inflammation. Effective application of MSCs in disease treatment relies on the production of relatively homogeneous cell population. However, the cellular heterogeneity and the differentiation trajectories of in vitro expanded MSCs remain largely unclear. We profiled the transcriptomes of 361 single MSCs derived from two umbilical cords (UC-MSCs). These UC-MSCs were harvested at different passages and stimulated with or without inflammatory cytokines. Weighted gene correlation network analysis revealed that UC-MSCs surprisingly possess only limited heterogeneity, regardless of donors, and passages. We also found that upon pretreatment with inflammatory cytokines (IFNγ and TNFα), a classical strategy that can improve the efficiency of MSC-based therapy, MSCs exhibited uniformed changes in gene expression. Cell cycle-based principal component analysis showed that the limited heterogeneity identified in these UC-MSCs was strongly associated with their entrance into the G2/M phase. This was further proven by the observation that one featured gene, CD168, was expressed in a cell cycle-dependent manner. When CD168high UC-MSCs were sorted and cultured in vitro, they again showed similar CD168 expression patterns. Our results demonstrated that in vitro expanded UC-MSCs are a well-organized population with limited heterogeneity dominated by cell cycle status. Thus, our studies provided information for standardization of MSCs for disease treatment.
Project description:Osteoarthritis (OA) has long been considered as a degenerative disease, but growing evidence suggests that inflammation plays a vital role in its pathogenesis. Unlike rheumatoid arthritis and other autoimmune diseases, inflammation in OA is chronic and, in relatively low grade, mainly mediated by the innate immune system, especially macrophages. However, due to its low abundance, there is a lack of systematic studies on macrophages in the OA condition. Here, we have used single-cell RNA sequencing analysis to gain insight into the heterogeneity and functional specialization of human knee macrophages. We also compared the gene expression profiles of macrophages in healthy people and OA patients and found the characteristic changes of special macrophages in the OA knee. We believe that this in-depth understanding of the basis of OA inflammation will bring hope for the development of new therapies.
Project description:Senescence of skeletal muscle (SkM) has been a primary contributor to senior weakness and disability in recent years. The gradually declining SkM function associated with senescence has recently been connected to an imbalance between damage and repair. Macrophages (Mac) are involved in SkM aging, and different macrophage subgroups hold different biological functions. Through comprehensive single-cell transcriptomic analysis, we first compared the metabolic pathways and biological functions of different types of cells in young (Y) and old (O) mice SkM. Strikingly, the Mac population in mice SkM was also explored, and we identified a unique Mac subgroup in O SkM characterized by highly expressed SPP1 with strong senescence and adipogenesis features. Further work was carried out on the metabolic and biological processes for these Mac subgroups. Besides, we verified that the proportion of the SPP1+ Mac was increased significantly in the quadriceps tissues of O mice, and the senotherapeutic drug combination dasatinib + quercetin (D + Q) could dramatically reduce its proportion. Our study provides novel insight into the potential role of SPP1+ Mac in SkM, which may serve as a senotherapeutic target in SkM aging.