scholarly journals Reference-based annotation of single cell transcriptomes identifies a profibrotic macrophage niche after tissue injury

2018 ◽  
Author(s):  
Dvir Aran ◽  
Agnieszka P. Looney ◽  
Leqian Liu ◽  
Valerie Fong ◽  
Austin Hsu ◽  
...  

AbstractMyeloid cells localize to peripheral tissues in a wide range of pathologic contexts. However, appreciation of distinct myeloid subtypes has been limited by the signal averaging inherent to bulk sequencing approaches. Here we applied single-cell RNA sequencing (scRNA-seq) to map cellular heterogeneity in lung fibrosis induced by bleomycin injury in mice. We first developed a computational framework that enables unbiased, granular cell-type annotation of scRNA-seq. This approach identified a macrophage subpopulation that was specific to injured lung and notable for high expression of Cx3cr1+ and MHCII genes. We found that these macrophages, which bear a gene expression profile consistent with monocytic origin, progressively acquire alveolar macrophage identity and localize to sites of fibroblast accumulation. Probing their functional role, in vitro studies showed a trophic effect of these cells on fibroblast activation, and ablation of Cx3cr1-expressing cells suppressed fibrosis in vivo. We also found by gene set analysis and immunofluorescence that markers of these macrophages were upregulated in samples from patients with lung fibrosis compared with healthy controls. Taken together, our results uncover a specific pathologic subgroup of macrophages with markers that could enable their therapeutic targeting for fibrosis.

2019 ◽  
Author(s):  
Teresa G Krieger ◽  
Stephan M Tirier ◽  
Jeongbin Park ◽  
Tanja Eisemann ◽  
Heike Peterziel ◽  
...  

AbstractGlioblastoma multiforme (GBM) are devastating neoplasms with high invasive capacity. GBM has been difficult to study in vitro. Therapeutic progress is also limited by cellular heterogeneity within and between tumors. To address these challenges, we present an experimental model using human cerebral organoids as a scaffold for patient-derived glioblastoma cell invasion. By tissue clearing and confocal microscopy, we show that tumor cells within organoids extend a network of long microtubes, recapitulating the in vivo behavior of GBM. Single-cell RNA-seq of GBM cells before and after co-culture with organoid cells reveals transcriptional changes implicated in the invasion process that are coherent across patient samples, indicating that GBM cells reactively upregulate genes required for their dispersion. Functional therapeutic targets are identified by an in silico receptor-ligand pairing screen detecting potential interactions between GBM and organoid cells. Taken together, our model has proven useful for studying GBM invasion and transcriptional heterogeneity in vitro, with applications for both pharmacological screens and patient-specific treatment selection at a time scale amenable to clinical practice.


2020 ◽  
Vol 22 (8) ◽  
pp. 1138-1149 ◽  
Author(s):  
Teresa G Krieger ◽  
Stephan M Tirier ◽  
Jeongbin Park ◽  
Katharina Jechow ◽  
Tanja Eisemann ◽  
...  

Abstract Background Glioblastoma (GBM) consists of devastating neoplasms with high invasive capacity, which have been difficult to study in vitro in a human-derived model system. Therapeutic progress is also limited by cellular heterogeneity within and between tumors, among other factors such as therapy resistance. To address these challenges, we present an experimental model using human cerebral organoids as a scaffold for patient-derived GBM cell invasion. Methods This study combined tissue clearing and confocal microscopy with single-cell RNA sequencing of GBM cells before and after co-culture with organoid cells. Results We show that tumor cells within organoids extend a network of long microtubes, recapitulating the in vivo behavior of GBM. Transcriptional changes implicated in the invasion process are coherent across patient samples, indicating that GBM cells reactively upregulate genes required for their dispersion. Potential interactions between GBM and organoid cells identified by an in silico receptor–ligand pairing screen suggest functional therapeutic targets. Conclusions Taken together, our model has proven useful for studying GBM invasion and transcriptional heterogeneity in vitro, with applications for both pharmacological screens and patient-specific treatment selection on a time scale amenable to clinical practice.


2020 ◽  
Author(s):  
Yun Gong ◽  
Junxiao Yang ◽  
Xiaohua Li ◽  
Cui Zhou ◽  
Yu Chen ◽  
...  

AbstractOsteoblasts are multifunctional bone cells, which play essential roles in bone formation, angiogenesis regulation, as well as maintenance of hematopoiesis. Although both in vivo and in vitro studies on mice have identified several potential osteoblast subtypes based on their different transition stages or biological responses to external stimuli, the categorization of primary osteoblast subtypes in vivo in humans has not yet been achieved. Here, we used single-cell RNA sequencing (scRNA-seq) to perform a systematic cellular taxonomy dissection of freshly isolated human osteoblasts. Based on the gene expression patterns and cell lineage reconstruction, we identified three distinct cell clusters including preosteoblasts, mature osteoblasts, and an undetermined rare osteoblast subpopulation. This novel subtype was mainly characterized by the nuclear receptor subfamily 4 group A member 1 and 2 (NR4A1 and NR4A2), and its existence was confirmed by immunofluorescence staining. Trajectory inference analysis suggested that the undetermined cluster, together with the preosteoblasts, are involved in the regulation of osteoblastogenesis and also give rise to mature osteoblasts. Investigation of the biological processes and signaling pathways enriched in each subpopulation revealed that in addition to bone formation, preosteoblasts and undetermined osteoblasts may also regulate both angiogenesis and hemopoiesis. Finally, we demonstrated that there are systematic differences between the transcriptional profiles of human osteoblasts in vivo and mouse osteoblasts both in vivo and in vitro, highlighting the necessity for studying bone physiological processes in humans rather than solely relying on mouse models. Our findings provide novel insights into the cellular heterogeneity and potential biological functions of human primary osteoblasts at the single-cell level, which is an important and necessary step to further dissect the biological roles of osteoblasts in bone metabolism under various (patho-) physiological conditions.


2021 ◽  
Author(s):  
Clara Alsinet ◽  
Maria Primo ◽  
Valentina Lorenzi ◽  
Andrew J Knights ◽  
Carmen Sancho-Serra ◽  
...  

Myeloid cells have a central role in homeostasis and tissue defence. Characterising the current in vitro protocols of myelopoiesis is imperative for their use in research and immunotherapy as well as for understanding the early stages of myeloid differentiation in humans. Here, we profiled the transcriptome of more than 400k cells and generated a robust molecular map of the differentiation of human induced pluripotent stem cells (iPSC) into macrophages. By integrating our in vitro datasets with in vivo single-cell developmental atlases, we found that in vitro macrophage differentiation recapitulates features of in vivo yolk sac hematopoiesis, which happens prior to the appearance of definitive hematopoietic stem cells (HSC). During in vitro myelopoiesis, a wide range of myeloid cells are generated, including erythrocytes, mast cells and monocytes, suggesting that, during early human development, the HSC-independent immune wave gives rise to multiple myeloid cell lineages. We leveraged this model to characterize the transition of hemogenic endothelium into myeloid cells, uncovering poorly described myeloid progenitors and regulatory programs. Taking advantage of the variety of myeloid cells produced, we developed a new protocol to produce type 2 conventional dendritic cells (cDC2) in vitro. We found that the underlying regulatory networks coding for myeloid identity are conserved in vivo and in vitro. Using genetic engineering techniques, we validated the effects of key transcription factors important for cDC2 and macrophage identity and ontogeny. This roadmap of early myeloid differentiation will serve as an important resource for investigating the initial stages of hematopoiesis, which are largely unexplored in humans, and will open up new therapeutic opportunities.


Blood ◽  
2021 ◽  
Author(s):  
Shu Sun ◽  
Chen Jin ◽  
Jia Si ◽  
Ying Lei ◽  
Kunying Chen ◽  
...  

Megakaryocytes (MKs), the platelet progenitor cell, play important roles in hematopoietic stem cell (HSC) maintenance and immunity. However, it is not known whether these diverse programs are executed by a single population or by distinct subsets of cells. Here, we manually-isolated primary CD41+ MKs from the bone marrow (BM) of mice and human donors based on ploidy (2N-32N), performed single-cell RNA sequencing analysis. We found that cellular heterogeneity existed within three distinct subpopulations possessing gene signatures related to platelet-generation, HSC niche interaction, and inflammatory responses, respectively. In situ immunostaining of mouse BM demonstrated that platelet-generation and HSC-niche related MKs were physically in close proximity to blood vessels and HSCs, respectively. Proplatelets, which could give rise to platelets under the blood shear forces, were predominantly formed on platelet-generation subset. Remarkably, the inflammatory responses subpopulation, consisting generally of low-ploidy LSP1+ and CD53+ MKs (≤8N), represented approximately 5% of total MKs in the BM. These MKs could specifically respond to pathogen infections in mice. Rapid expansion of this population was accompanied by strong upregulation of a pre-existing PU.1 and IRF-8-associated monocytic-like transcriptional program involved in pathogen recognition and clearance, as well as antigen presentation. Consistently, isolated primary CD53+ cells were capable to engulf and digest bacteria and to stimulate T cells in vitro. Together, our findings uncover new molecular, spatial, and functional heterogeneity within MKs in vivo and demonstrate the existence of a specialized MK subpopulation that may act as a new type of immune cell.


1991 ◽  
Vol 30 (01) ◽  
pp. 35-39 ◽  
Author(s):  
H. S. Durak ◽  
M. Kitapgi ◽  
B. E. Caner ◽  
R. Senekowitsch ◽  
M. T. Ercan

Vitamin K4 was labelled with 99mTc with an efficiency higher than 97%. The compound was stable up to 24 h at room temperature, and its biodistribution in NMRI mice indicated its in vivo stability. Blood radioactivity levels were high over a wide range. 10% of the injected activity remained in blood after 24 h. Excretion was mostly via kidneys. Only the liver and kidneys concentrated appreciable amounts of radioactivity. Testis/soft tissue ratios were 1.4 and 1.57 at 6 and 24 h, respectively. Testis/blood ratios were lower than 1. In vitro studies with mouse blood indicated that 33.9 ±9.6% of the radioactivity was associated with RBCs; it was washed out almost completely with saline. Protein binding was 28.7 ±6.3% as determined by TCA precipitation. Blood clearance of 99mTc-l<4 in normal subjects showed a slow decrease of radioactivity, reaching a plateau after 16 h at 20% of the injected activity. In scintigraphic images in men the testes could be well visualized. The right/left testis ratio was 1.08 ±0.13. Testis/soft tissue and testis/blood activity ratios were highest at 3 h. These ratios were higher than those obtained with pertechnetate at 20 min post injection.99mTc-l<4 appears to be a promising radiopharmaceutical for the scintigraphic visualization of testes.


Author(s):  
Roohi Mohi-ud-din ◽  
Reyaz Hassan Mir ◽  
Prince Ahad Mir ◽  
Saeema Farooq ◽  
Syed Naiem Raza ◽  
...  

Background: Genus Berberis (family Berberidaceae), which contains about 650 species and 17 genera worldwide, has been used in folklore and various traditional medicine systems. Berberis Linn. is the most established group among genera with around 450-500 species across the world. This comprehensive review will not only help researchers for further evaluation but also provide substantial information for future exploitation of species to develop novel herbal formulations. Objective: The present review is focussed to summarize and collect the updated review of information of Genus Berberis species reported to date regarding their ethnomedicinal information, chemical constituents, traditional/folklore use, and reported pharmacological activities on more than 40 species of Berberis. Conclusion: A comprehensive survey of the literature reveals that various species of the genus possess various phytoconstituents mainly alkaloids, flavonoid based compounds isolated from different parts of a plant with a wide range of pharmacological activities. So far, many pharmacological activities like anti-cancer, anti-hyperlipidemic, hepatoprotective, immunomodulatory, anti-inflammatory both in vitro & in vivo and clinical study of different extracts/isolated compounds of different species of Berberis have been reported, proving their importance as a medicinal plant and claiming their traditional use.


2019 ◽  
Vol 20 (12) ◽  
pp. 1227-1243
Author(s):  
Hina Qamar ◽  
Sumbul Rehman ◽  
D.K. Chauhan

Cancer is the second leading cause of morbidity and mortality worldwide. Although chemotherapy and radiotherapy enhance the survival rate of cancerous patients but they have several acute toxic effects. Therefore, there is a need to search for new anticancer agents having better efficacy and lesser side effects. In this regard, herbal treatment is found to be a safe method for treating and preventing cancer. Here, an attempt has been made to screen some less explored medicinal plants like Ammania baccifera, Asclepias curassavica, Azadarichta indica, Butea monosperma, Croton tiglium, Hedera nepalensis, Jatropha curcas, Momordica charantia, Moringa oleifera, Psidium guajava, etc. having potent anticancer activity with minimum cytotoxic value (IC50 >3μM) and lesser or negligible toxicity. They are rich in active phytochemicals with a wide range of drug targets. In this study, these medicinal plants were evaluated for dose-dependent cytotoxicological studies via in vitro MTT assay and in vivo tumor models along with some more plants which are reported to have IC50 value in the range of 0.019-0.528 mg/ml. The findings indicate that these plants inhibit tumor growth by their antiproliferative, pro-apoptotic, anti-metastatic and anti-angiogenic molecular targets. They are widely used because of their easy availability, affordable price and having no or sometimes minimal side effects. This review provides a baseline for the discovery of anticancer drugs from medicinal plants having minimum cytotoxic value with minimal side effects and establishment of their analogues for the welfare of mankind.


Author(s):  
Shangfei Wei ◽  
Tianming Zhao ◽  
Jie Wang ◽  
Xin Zhai

: Allostery is an efficient and particular regulatory mechanism to regulate protein functions. Different from conserved orthosteric sites, allosteric sites have distinctive functional mechanism to form the complex regulatory network. In drug discovery, kinase inhibitors targeting the allosteric pockets have received extensive attention for the advantages of high selectivity and low toxicity. The approval of trametinib as the first allosteric inhibitor validated that allosteric inhibitors could be used as effective therapeutic drugs for treatment of diseases. To date, a wide range of allosteric inhibitors have been identified. In this perspective, we outline different binding modes and potential advantages of allosteric inhibitors. In the meantime, the research processes of typical and novel allosteric inhibitors are described briefly in terms of structureactivity relationships, ligand-protein interactions and in vitro and in vivo activity. Additionally, challenges as well as opportunities are presented.


2020 ◽  
Vol 18 ◽  
Author(s):  
Zirui Zhang ◽  
Shangcong Han ◽  
Panpan Liu ◽  
Xu Yang ◽  
Jing Han ◽  
...  

Background: Chronic inflammation and lack of angiogenesis are the important pathological mechanisms in deep tissue injury (DTI). Curcumin is a well-known anti-inflammatory and antioxidant agent. However, curcumin is unstable under acidic and alkaline conditions, and can be rapidly metabolized and excreted in the bile, which shortens its bioactivity and efficacy. Objective: This study aimed to prepare curcumin-loaded poly (lactic-co-glycolic acid) nanoparticles (CPNPs) and to elucidate the protective effects and underlying mechanisms of wound healing in DTI models. Methods: CPNPs were evaluated for particle size, biocompatibility, in vitro drug release and their effect on in vivo wound healing. Results : The results of in vivo wound closure analysis revealed that CPNP treatments significantly improved wound contraction rates (p<0.01) at a faster rate than other three treatment groups. H&E staining revealed that CPNP treatments resulted in complete epithelialization and thick granulation tissue formation, whereas control groups resulted in a lack of compact epithelialization and persistence of inflammatory cells within the wound sites. Quantitative real-time PCR analysis showed that treatment with CPNPs suppressed IL-6 and TNF-α mRNA expression, and up-regulated TGF-β, VEGF-A and IL-10 mRNA expression. Western blot analysis showed up-regulated protein expression of TGF-β, VEGF-A and phosphorylatedSTAT3. Conclusion: Our results showed that CPNPs enhanced wound healing in DTI models, through modulation of the JAK2/STAT3 signalling pathway and subsequent upregulation of pro-healing factors.


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