Single-cell RNA sequencing deciphers transcriptional profiles of hepatocytes in mouse with hepatic alveolar echinococcosis / 中国血吸虫病防治杂志

Objective To investigate the cell composition and the transcriptional characteristics in microenvironments of hepatic tissues in mice at late stage of Echinococcus multilocularis infection at a single-cell level. Methods Peri-lesion and paired distal hepatic specimens were collected from two BALB/c mice (6 to 8 weeks old) infected with E. multilocularis for single-cell RNA sequencing. The Seurat package in the R software was employed for quality control of data, multi-sample integration and correction of batch effects, and uniform manifold approximation and projection (UMAP) algorithm was used for cell clustering. Cell types were annotated using classical marker genes. Differentially expressed genes were screened in each cell type through differential gene expression analysis, and the biological roles of cells were predicted using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. Results A total of 43 710 cells from peri-lesion and distal hepatic tissues of E. multilocularis-infected mice were analyzed, and were classified into 11 cell types, including neutrophils, T cells, macrophages, granulocyte-monocyte progenitor cells, B cells, plasma cells, basophils, hepatic stellate cells, endothelial cells, hepatocytes, and platelets. T cells were the largest population of immune cells in the microenvironment of hepatic tissues, including five CD4+ T cell subsets, two CD8+ T cell subsets and phosphoantigen-reactive γδT cells. The proportions of CD4+ helper T cells and cytotoxic CD4+ T cells decreased and the proportion of T helper 2 (Th2) cells increased in peri-lesion tissues relative to distal hepatic tissues. In addition, the differentially expressed genes in Th2 cells were associated with negative regulation of the immune system, and the highly expressed genes in cytotoxic CD4+ T cells correlated with activation of the immune system. Conclusions Single-cell RNA sequencing deciphers the cell composition and distribution in microenvironments of hepatic tissues from mice infected with E. multilocularis, and the increased proportion of Th2 cells in peri-lesion hepatic tissues may be associated with formation of immunosuppressive microenvironments.

Evaluation of peripheral blood T-lymphocyte subpopulations features in patients with hepatitis B virus-related acute-on-chronic liver failure based on single-cell sequencing technology / 中华肝脏病杂志

Objective: T lymphocyte exhaustion is an important component of immune dysfunction. Therefore, exploring peripheral blood-exhausted T lymphocyte features in patients with hepatitis B virus-related acute-on-chronic liver failure may provide potential therapeutic target molecules for ACLF immune dysfunction. Methods: Six cases with HBV-ACLF and three healthy controls were selected for T-cell heterogeneity detection using the single-cell RNA sequencing method. In addition, exhausted T lymphocyte subpopulations were screened to analyze their gene expression features, and their developmental trajectories quasi-timing. An independent sample t-test was used to compare the samples between the two groups. Results: Peripheral blood T lymphocytes in HBV-ACLF patients had different differentiation trajectories with different features distinct into eight subpopulations. Among them, the CD4(+)TIGIT(+) subsets (P = 0.007) and CD8(+)LAG3(+) (P = 0.010) subsets with highly exhausted genes were significantly higher than those in healthy controls. Quasi-time analysis showed that CD4(+)TIGIT(+) and CD8(+)LAG3(+) subsets appeared in the late stage of T lymphocyte differentiation, suggesting the transition of T lymphocyte from naïve-effector-exhausted during ACLF pathogenesis. Conclusion: There is heterogeneity in peripheral blood T lymphocyte differentiation in patients with HBV-ACLF, and the number of exhausted T cells featured by CD4(+)TIGIT(+)T cell and CD8(+)LAG3(+) T cell subsets increases significantly, suggesting that T lymphocyte immune exhaustion is involved in the immune dysfunction of HBV-ACLF, thereby identifying potential effective target molecules for improving ACLF patients' immune function.

Imputation method for dropout in single-cell transcriptome data / 生物医学工程学杂志

Single-cell transcriptome sequencing (scRNA-seq) can resolve the expression characteristics of cells in tissues with single-cell precision, enabling researchers to quantify cellular heterogeneity within populations with higher resolution, revealing potentially heterogeneous cell populations and the dynamics of complex tissues. However, the presence of a large number of technical zeros in scRNA-seq data will have an impact on downstream analysis of cell clustering, differential genes, cell annotation, and pseudotime, hindering the discovery of meaningful biological signals. The main idea to solve this problem is to make use of the potential correlation between cells and genes, and to impute the technical zeros through the observed data. Based on this, this paper reviewed the basic methods of imputing technical zeros in the scRNA-seq data and discussed the advantages and disadvantages of the existing methods. Finally, recommendations and perspectives on the use and development of the method were provided.

Single-cell profiling reveals a potent role of quercetin in promoting hair regeneration

Hair loss affects millions of people at some time in their life, and safe and efficient treatments for hair loss are a significant unmet medical need. We report that topical delivery of quercetin (Que) stimulates resting hair follicles to grow with rapid follicular keratinocyte proliferation and replenishes perifollicular microvasculature in mice. We construct dynamic single-cell transcriptome landscape over the course of hair regrowth and find that Que treatment stimulates the differentiation trajectory in the hair follicles and induces an angiogenic signature in dermal endothelial cells by activating HIF-1α in endothelial cells. Skin administration of a HIF-1α agonist partially recapitulates the pro-angiogenesis and hair-growing effects of Que. Together, these findings provide a molecular understanding for the efficacy of Que in hair regrowth, which underscores the translational potential of targeting the hair follicle niche as a strategy for regenerative medicine, and suggest a route of pharmacological intervention that may promote hair regrowth.

Advances in single-cell RNA sequencing in the retina / 中华眼底病杂志

Retina is composed of a heterogeneous population of cell types, each with a unique biological function. Even if the same type of cells, due to genetic heterogeneity will lead to cell function differences. In the past, traditional molecular biological methods cannot resolve variations in their functional roles that arise from these differences, and some cells are difficult to define due to the lack of specific molecular markers or the scarcity of numbers, which hindered the understanding and research of these cells. With the development of biotechnology, single-cell RNA sequencing can analyze and resolve differences in single-cell transcriptome expression profiles, characterize intracellular population heterogeneity, identify new and rare cell subtypes, and more definitely define the characteristics of each cell type. It clarifies the origin, function, and variations in cell phenotypes. Other attributes include pinpointing both disease-related characteristics of cell subtypes and specific differential gene expression patterns, to deepen our understanding of the causes and progression of diseases, as well as to aid clinical diagnosis and targeted therapy.

Application of single cell RNA sequencing in the treatment of diabetes / 中华内分泌代谢杂志

Single-cell RNA sequencing (scRNA-seq) is used for transcriptome profiling at the individual cell level, which is capable of screening in differentially gene expression that results from genetic mutation. Islet-based developmental atlas and heterogeneity characterization are currently the main applications of scRNA-seq in diabetes. scRNA-seq also can be used to mark and purify the functional β cells from resident adult stem cells in the pancreatic islets, which is expected to improve the outcome of islet β cells transplantation in type 1 diabetic patients. In addition, the technique can aid in learning diabetic β cell dedifferentiation and immunomodulatory functions. Although the study of scRNA-seq in diabetic retinopathy, nephropathy, atherosclerosis, and peripheral neuropathy is still at a nascent stage, scRNA-seq has great potential in a wide range of biomedical and clinical applications.

Investigation of endothelial cell pathological characteristics in murine choroidal neovascularization model based on single-cell RNA sequencing / 中华实验眼科杂志

Objective:To investigate the molecular expression and pathological features of endothelial cell (EC) in a murine model of choroidal neovascularization (CNV) based on single-cell RNA sequencing (scRNA-seq).Methods:Six C57BL/6 mice aged 6-8 weeks were randomly divided into two groups, with 3 mice in each group.Bilateral eyeballs were enucleated.The choroidal tissues from the two groups were isolated by shearing the complex and scraping the choroid, respectively.Single-cell suspension was prepared by continuous digestion with trypsin/type Ⅰ collagenase at 37 ℃, and the cell viability and EC ratio were detected by flow cytometry to determine the preparation method of single-cell suspension.Another 6 mice were randomly assigned into the control group and the CNV group, with 3 mice in each group.The CNV model was induced by laser photocoagulation and single-cell suspensions were prepared 7 days after modeling.Gene expression library construction was performed using the Chromi-um (10x Genomics) instrument.High throughput sequencing was performed using the Illumina Novaseq6000 to obtain the expression matrix.The EC subpopulations were classified according to previous researches and the Cellmarker database.Pseudo-time analysis was performed in EC, revealing the gene expression matrix of different states.CNV-EC were further selected with preliminary analysis of the expression characteristics.Another 6 mice were selected to establish the CNV model and eyeball frozen sections were prepared 7 days after modeling.Expression and distribution as well as the area percentage of EC marker Pecam1, mitochondrial outer membrane proteins Tomm20 and mt-Co1, and capillary markers Kdr and Plvap were observed by immunofluorescence staining, and the vascular diameter was calculated.The use and care of animals followed the ARVO statement.This study protocol was approved by the Experimental Animal Welfare and Ethics Committee of Air Force Military Medical University (No.20200181).Results:The cell viability of the single-cell suspension prepared from choroidal-scleral fragments and choroidal scrapings was 99.4% and 99.1%, respectively, both of which met the sequencing requirements.The percentage of EC detected by flow cytometry was approximately 1.58%.The scRNA-seq result revealed that both the normal control and CNV groups contained 13 choroidal cell clusters.Compared with the normal control group, the proportions of rod/cone photoreceptor cells, EC and hematopoietic cells all increased, while the retinal pigment epithelium (RPE) and Schwan cells reduced in the CNV group.Among all clusters, EC constituted 18.4%.The pseudo-time analysis demonstrated that EC could be further divided into 4 states.The percentage of state 2 EC was 29.1% in the CNV group, which was significantly higher than 9.5% in the normal control group.Differentially expressed gene analysis showed that the expression of mitochondrion-related genes, including mt-Nd4 and mt-Atp6, were upregulated in state 2 EC, while capillary-related genes, including Kdr and Esm1, were downregulated.Immunofluorescent staining revealed that the area of Tomm20 and mt-Co1 in Pecam1-positive EC in the CNV area was (19.50±4.68)% and (4.64±2.82)%, respectively, which were both higher than (3.00±2.09)% and (0.18±0.34)% in normal area ( t=7.88, 3.84; both at P<0.01). The area of Kdr and Plvap in Pecam1-positive EC in the CNV area was (1.50±0.29)% and (0.79±0.97)%, respectively, which were both lower than (31.30±5.44)% and (10.43±2.28)% in the normal area ( t=13.40, 9.48; both at P<0.01). The vascular diameter in the CNV area was (5.52±1.85)μm, which was larger than (4.21±1.84)μm in the normal area ( t=9.57, P<0.001). Conclusions:When CNV occurs, the proportion of EC in choroid increases, and CNV-EC shows pathologic features of mitochondrial metabolic activation and loss of capillary properties, suggesting the mitochondrial activation of EC may play a role in the formation of CNV.

Identification of SULF1 as a Shared Gene in Idiopathic Pulmonary Fibrosis and Lung Adenocarcinoma / 中国肺癌杂志

BACKGROUND@#Idiopathic pulmonary fibrosis (IPF) is an idiopathic chronic, progressive interstitial lung disease with a diagnosed median survival of 3-5 years. IPF is associated with an increased risk of lung cancer. Therefore, exploring the shared pathogenic genes and molecular pathways between IPF and lung adenocarcinoma (LUAD) holds significant importance for the development of novel therapeutic approaches and personalized precision treatment strategies for IPF combined with lung cancer.@*METHODS@#Bioinformatics analysis was conducted using publicly available gene expression datasets of IPF and LUAD from the Gene Expression Omnibus (GEO) database. Weighted gene co-expression network analysis was employed to identify common genes involved in the progression of both diseases, followed by functional enrichment analysis. Subsequently, additional datasets were used to pinpoint the core shared genes between the two diseases. The relationship between core shared genes and prognosis, as well as their expression patterns, clinical relevance, genetic characteristics, and immune-related functions in LUAD, were analyzed using The Cancer Genome Atlas (TCGA) database and single-cell RNA sequencing datasets. Finally, potential therapeutic drugs related to the identified genes were screened through drug databases.@*RESULTS@#A total of 529 shared genes between IPF and LUAD were identified. Among them, SULF1 emerged as a core shared gene associated with poor prognosis. It exhibited significantly elevated expression levels in LUAD tissues, concomitant with high mutation rates, genomic heterogeneity, and an immunosuppressive microenvironment. Subsequent single-cell RNA-seq analysis revealed that the high expression of SULF1 primarily originated from tumor-associated fibroblasts. This study further demonstrated an association between SULF1 expression and tumor drug sensitivity, and it identified potential small-molecule drugs targeting SULF1 highly expressed fibroblasts.@*CONCLUSIONS@#This study identified a set of shared molecular pathways and core genes between IPF and LUAD. Notably, SULF1 may serve as a potential immune-related biomarker and therapeutic target for both diseases.

Preliminary Results of Single-cell Transcriptome Sequencing in Renal Arterial Lesions of Takayasu Arteritis / 中国医学科学院学报

Objective To explore the preliminary application of single-cell RNA sequencing (scRNA-seq) in the renal arterial lesions in Takayasu arteritis (TA) patients. Methods This study included 2 TA patients with renal artery stenosis treated by bypass surgery in the Department of Vascular Surgery,Beijing Hospital.The obtained 2 renal artery samples were digested with two different protocols (GEXSCOPE kit and self-made digestion liquid) before scRNA-seq and bioinformatics analysis. Results A total of 2920 cells were obtained for further analysis.After unbiased cluster analysis,2 endothelial cell subsets,2 smooth muscle cell subsets,1 fibroblast subset,2 mononuclear macrophage subsets,1 T cell subset,and 1 undefined cell subset were identified.Among them,the two subsets of smooth muscle cells were contractile and secretory,respectively.The results of scRNA-seq indicated that enzymatic hydrolysis with GEXSCOPE kit produced a large number of endothelial cells (57.46%) and a small number of immune cells (13.21%).However,immune cells (34.64%) were dominant in the cells obtained by enzymatic hydrolysis with self-made digestive liquid. Conclusion scRNA-seq can be employed to explore the cellular heterogeneity of diseased vessels in TA patients.Different enzymatic digestion protocols may impact the proportion of different cells.

Distinct mononuclear diploid cardiac subpopulation with minimal cell-cell communications persists in embryonic and adult mammalian heart / 医学前沿

A small proportion of mononuclear diploid cardiomyocytes (MNDCMs), with regeneration potential, could persist in adult mammalian heart. However, the heterogeneity of MNDCMs and changes during development remains to be illuminated. To this end, 12 645 cardiac cells were generated from embryonic day 17.5 and postnatal days 2 and 8 mice by single-cell RNA sequencing. Three cardiac developmental paths were identified: two switching to cardiomyocytes (CM) maturation with close CM-fibroblast (FB) communications and one maintaining MNDCM status with least CM-FB communications. Proliferative MNDCMs having interactions with macrophages and non-proliferative MNDCMs (non-pMNDCMs) with minimal cell-cell communications were identified in the third path. The non-pMNDCMs possessed distinct properties: the lowest mitochondrial metabolisms, the highest glycolysis, and high expression of Myl4 and Tnni1. Single-nucleus RNA sequencing and immunohistochemical staining further proved that the Myl4+Tnni1+ MNDCMs persisted in embryonic and adult hearts. These MNDCMs were mapped to the heart by integrating the spatial and single-cell transcriptomic data. In conclusion, a novel non-pMNDCM subpopulation with minimal cell-cell communications was unveiled, highlighting the importance of microenvironment contribution to CM fate during maturation. These findings could improve the understanding of MNDCM heterogeneity and cardiac development, thus providing new clues for approaches to effective cardiac regeneration.

Liver macrophages show an immunotolerance phenotype in nonalcoholic fatty liver combined with Porphyromonas gingivalis-lipopolysaccharide infection / 华西口腔医学杂志

OBJECTIVES@#This study aimed to explore the functions and potential regulatory targets of local macrophages in nonalcoholic fatty liver combined with Porphyromonas gingivalis (P. gingivalis)infection.@*METHODS@#Single-cell RNA sequencing was used to analyze the phenotypes and functional changes in various cells in the liver tissue of nonalcoholic steatohepatitis (NASH) mice fed with P. gingivalis. Real-time polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay, and immunofluorescence staining were applied to observe the inflammation and expression levels of macrophage antigen presenting functional markers in the NASH liver. Oil red staining was performed to observe the accumulation of local adipose tissue in the NASH liver. Results were verified through RT-PCRand RNA sequencing using P. gingivalis-lipopolysaccharide treated mouse peritoneal macrophages.@*RESULTS@#In comparison with healthy livers with Kupffer cells, the NASH liver combined with P. gingivalis infection-related macrophages showed significant heterogeneity. C1qb, C1qc, Mafb, Apoe, and Cd14 were highly expressed, but Cd209a, H2-Aa, H2-Ab1, and H2-DMb1, which are related to the antigen presentation function, were weakly expressed. Further in vivo and in vitro investigations indicated that the activation and infiltration of these macrophages may be due to local P. gingivalis-lipopolysaccharide accumulation.@*CONCLUSIONS@#P. gingivalis-lipopolysaccharide induces a local macrophage immunotolerance phenotype in nonalcoholic fatty liver, which may be the key mechanism of periodontitis pathogen infection that promotes NASH inflammation and pathogenesis. This study further clarifies the dysfunction and regulatory mechanisms of macrophages in the pathogenesis of P. gingivalis-infected NASH, thereby providing potential therapeutic targets for its clinical treatment.

Single cell RNA sequencing technology applicated for drug discovery / 药学学报

Single cell RNA sequencing (scRNA-seq) is an advanced technology to study the transcriptome information at the single cell level. The application of this technology can attribute to analyze the heterogeneous map of cells in the process of disease development, and precisely identify the specific cell subsets that are responsive to pharmacological therapy. Currently, scRNA-seq technology has been widely applied in the field of drug research, including studies on therapeutic targets, drug-induced adverse reactions, drug resistance and vaccine. This work reviews the application of scRNA-seq technology in drug discovery, which offers a scientific basis for personalized and accurate medication therapy.

Application of Single-cell RNA Sequencing Technology to Exploring Cardioprotective Mechanism of Chinese Medicine After Myocardial Infarction： A Rewiew / 中国实验方剂学杂志

The pathological changes of the heart after myocardial infarction （MI） are complex， involving multiple molecular mechanisms and various cells， such as myocardial cells， endothelial cells， fibroblasts， and macrophages. With multiple targets， Chinese medicine demonstrates ideal cardioprotective effect. However， the complex mechanism of multi-component Chinese medicine formulas has not been elucidated， thus limiting the further application. The high-throughput single-cell RNA sequencing （scRNA-seq） technology offers single-cell transcriptome analysis of hundreds of drugs under different processing conditions in a single experiment and identifies the differences in the response of different cells and cell subtypes to drug treatment. scRNA-seq technology helps us to understand the exact cellular and molecular mechanisms of cardiac remodeling from acute ischemic events to chronic cardiac scarring. The application of scRNA-seq to studying the cardioprotective mechanism of Chinese medicine after MI can boost the development of Chinese medicine， help obtain richer， more accurate and comprehensive information. It can give us a clear insight into the mechanism of Chinese medicine based on complex network. In this study， we summarized the research on cardioprotective mechanism of Chinese medicine and introduced the development of scRNA-seq technology and the application to MI research. Finally， we explored the possible application prospects of scRNA-seq in the research on cardioprotective mechanism of Chinese medicine after MI， hoping to provide ideas for the modernization of Chinese medicine.

Research Progress of Single-cell Transcriptome Sequencing in Immune Microenvironment of Nasopharyngeal Carcinoma / 肿瘤防治研究

We analyze the recent research progress of single-cell transcriptome sequencing of nasopharyngeal carcinoma (NPC), dissect its tumor immune microenvironment, and focus on the role of myeloid cells, T cells, B cells, NK cells, and fibroblasts in the mechanism of action in NPC tissues to provide reference for the diagnosis, treatment, and prognosis prediction of NPC.

Single-cell transcriptome analysis of T cells in thyroid and peripheral blood of patients with Hashimoto′s thyroiditis / 中华内分泌代谢杂志

Objective:To construct single-cell transcription landscape of T cell in peripheral blood mononuclear cells(PBMCs) and thyroid tissue of patients with Hashimoto ′s thyroiditis(HT), and to analyze the changes in the proportion and functionality of T cell clusters in HT disease state.Methods:Single cell RNA sequencing was performed on PBMCs and thyroid tissue from 5 HT patients. Single cell RNA sequencing data of PBMCs from 5 healthy individuals were retrieved from public databases. After preliminary clustering, the clusters expressing CD3E were extracted and clustering again, and the names of each cluster were determined according to the known cell markers. The proportion of each cell subtype was compared, and the differentially expressed genes in different samples were analyzed.Results:After quality control, the 71 533 T cells were classified into 19 cell clusters. Among them, the proportion and function of C1_CD4 + Naive T cell clusters, C3_CD4 + Treg cell clusters, C7_CD8 + Naive T cell clusters, C8_GNLY -CD8 + T cell clusters, C10_RORC + CD8 + T cell clusters, C11_ GZMK + CD8 + T cell clusters, C12_CCL4 + CD8 + T cell clusters, and C18_PTGDS + NK cell clusters in thyroid tissue of HT patients were significantly different from those in PBMCs of healthy controls and HT patients. Conclusion:The proportion of multiple T cells in thyroid tissue of HT patients were significantly different from those in PBMCs. Among them, the proportion of three of CD8 + T cell subsets with high expression of cell killing-related genes in thyroid tissue T cells of HT patients is higher than that in PBMCs T cells, and it is statistically significant. In addition, the functionality of various T cells in the thyroid tissue of HT patients are also significantly different from those in PBMCs. A cluster of GZMK + CD8 + T cells showes significantly lower expression of genes related to PD1 pathway in thyroid tissues of HT patients compared with cells in PBMCs of HT patients, also a cluster of CCL4 + CD8 + T cells showes significantly lower expression of genes related to IL-12 pathway.

Advances in single-cell RNA sequencing for Kawasaki disease / 国际儿科学杂志

Kawasaki disease, an acute self-limited systematic vasculitis, predominantly affects children under 5 years old.One of the most common complications is coronary artery lesions.Currently, the pathogenesis mechanism of Kawasaki disease is considered to be multifactorial, including genetic susceptibility, impaired immune response, inflammatory injury and so on.Over the past decade, by interpreting the unique gene expression pattern on single-cell level, single-cell RNA sequencing is able to identify new or rare cell subsets and construct cell trajectories.These applications are widely applied to researches of cardiovascular diseases.This review summarizes the development of single-cell RNA sequencing and its applications in researches of the pathogenesis of Kawasaki disease, including animal model and acute phase of Kawasaki disease.

Macrophage differential genes and their functions in silicosis based on single cell RNA sequencing and spatial transcriptome sequencing / 环境与职业医学

Background The rise of single cell RNA sequencing (scRNA-seq) and spatial transcriptome sequencing technologies has allowed for intensive study of lung diseases, but both have been poorly studied in silicosis. Objective To explore differentially expressed genes DEGs in silicosis macrophages by scRNA-seq combined with spatial transcriptome sequencing and analyze the potential diagnostic genes. Methods Male C57BL/6 mice (5-6 weeks old, 22-30 g) were randomly divided into 4 groups: normal saline (NS) group for 7 d, NS group for 56 d, SiO2 group for 7 d, and SiO2 group for 56 d, with 1 mouse in each group. A silicosis model was constructed by tracheal drip injection of SiO2 suspension (0.2 g·kg−1, 50 g·cm−2), and the control mice were given the same volume of NS. The right lung was removed for scRNA-seq and the left lung for spatial transcriptome sequencing on day 7 and day 56, respectively. Cell populations were captured using principal component analysis techniques and dimensionality reduction of uniform manifold approximation and projection. The Find Markers function in R language was applied to analyze the DEGs changes of macrophages in two groups of lung tissues, and the corresponding DEGs were subjected to Gene Ontology enrichment analysis and Kyoto Encyclopedia of Genes and Genomes signaling pathway analysis, while STRING and CytoHubba plug-ins of Cytoscape software were applied to protein-protein interaction network analysis to screen out key (Hub) genes. Spatial transcriptome sequencing was used to explore the original location of Hub genes on lung tissue sections and their mapping in lung macrophages. Finally, the correlation of Hub gene expression levels in lung tissues of silicosis patients and mouse silicosis models was verified, the diagnostic efficacy of Hub gene using subject operating characteristic curves (ROC). In vitro experiments by applying cell viability assay were conducted to verify the changes in viability of mouse macrophages (RAW264.7) under SiO2 stimulation. Results The scRNA-seq revealed a total of 20 clusters captured and defined. The results of scRNA-seq and spatial transcriptome sequencing showed an increased number of macrophages in the lung tissue of the SiO2 group compared to the NS group and clustered in the focal areas. Among the 97 macrophage DEGs screened out, 75 were up-regulated genes, and mainly enriched in chemotaxis and migration of neutrophils, chemokine receptor binding, tumor necrosis factor signaling pathway, cytokine-cytokine receptor interaction pathway, and interleukin-17 signaling pathway; and 22 were down-regulated genes, and mainly enriched in late endosomes, peroxisome proliferator-activated receptors signaling pathway, and alcoholic liver disease signaling pathway. A total of 2 core modules and 3 Hub genes were screened out, including Ccl2, Ccl7, and Ptgs2. The scRNA-seq showed that they were expressed at elevated levels in the SiO2 group compared to the NS group and clustered in additional macrophages, and the spatial transcriptome sequencing showed that they clustered in inflammatory areas with nodular lesions. The CCL7 and PTGS2 expressions were increased in the lung tissue of SiO2 patients compared with the healthy subjects, and the areas under the working curve of the subjects were 0.850 and 0.786, respectively. The viability of RAW264.7 cells was enhanced under SiO2 stimulation at 3 h, 6 h, and 12 h compared to those without the stimulation (P<0.05). Conclusion Bioinformatics screening have identified 3 Hub genes (Ccl2, Ccl7, and Ptgs2)and 2 potential diagnostic genes (CCL7 and PTGS2) in the lung tissue of silicosis mice, which may be potential molecular markers of early-stage silicosis with implications for the development and prognosis of silicosis.

GranatumX: A Community-engaging, Modularized, and Flexible Webtool for Single-cell Data Analysis / 基因组蛋白质组与生物信息学报·英文版

We present GranatumX, a next-generation software environment for single-cell RNA sequencing (scRNA-seq) data analysis. GranatumX is inspired by the interactive webtool Granatum. GranatumX enables biologists to access the latest scRNA-seq bioinformatics methods in a web-based graphical environment. It also offers software developers the opportunity to rapidly promote their own tools with others in customizable pipelines. The architecture of GranatumX allows for easy inclusion of plugin modules, named Gboxes, which wrap around bioinformatics tools written in various programming languages and on various platforms. GranatumX can be run on the cloud or private servers and generate reproducible results. It is a community-engaging, flexible, and evolving software ecosystem for scRNA-seq analysis, connecting developers with bench scientists. GranatumX is freely accessible at http://garmiregroup.org/granatumx/app.

Single-cell Transcriptomes Reveal Characteristics of MicroRNAs in Gene Expression Noise Reduction / 基因组蛋白质组与生物信息学报·英文版

Isogenic cells growing in identical environments show cell-to-cell variations because of the stochasticity in gene expression. High levels of variation or noise can disrupt robust gene expression and result in tremendous consequences for cell behaviors. In this work, we showed evidence from single-cell RNA sequencing data analysis that microRNAs (miRNAs) can reduce gene expression noise at the mRNA level in mouse cells. We identified that the miRNA expression level, number of targets, target pool abundance, and miRNA-target interaction strength are the key features contributing to noise repression. miRNAs tend to work together in cooperative subnetworks to repress target noise synergistically in a cell type-specific manner. By building a physical model of post-transcriptional regulation and observing in synthetic gene circuits, we demonstrated that accelerated degradation with elevated transcriptional activation of the miRNA target provides resistance to extrinsic fluctuations. Together, through the integrated analysis of single-cell RNA and miRNA expression profiles, we demonstrated that miRNAs are important post-transcriptional regulators for reducing gene expression noise and conferring robustness to biological processes.

A review on integration methods for single-cell data / 生物医学工程学杂志

The emergence of single-cell sequencing technology enables people to observe cells with unprecedented precision. However, it is difficult to capture the information on all cells and genes in one single-cell RNA sequencing (scRNA-seq) experiment. Single-cell data of a single modality cannot explain cell state and system changes in detail. The integrative analysis of single-cell data aims to address these two types of problems. Integrating multiple scRNA-seq data can collect complete cell types and provide a powerful boost for the construction of cell atlases. Integrating single-cell multimodal data can be used to study the causal relationship and gene regulation mechanism across modalities. The development and application of data integration methods helps fully explore the richness and relevance of single-cell data and discover meaningful biological changes. Based on this, this article reviews the basic principles, methods and applications of multiple scRNA-seq data integration and single-cell multimodal data integration. Moreover, the advantages and disadvantages of existing methods are discussed. Finally, the future development is prospected.