Study on intercellular communication and key genes of smooth muscle cells in human coronary atherosclerosis based on single cell sequencing technology / 上海交通大学学报（医学版）

Objective·To use single-cell RNA sequencing(scRNA-Seq)technology to interpret the cellular communication landscape of coronary atherosclerosis(CA),and to explore the dominant cell subsets and their key genes.Methods·The GSE131778 data set was downloaded and preprocessed,and quality controlling,dimension reduction clustering and annotation were carried out.Then cell communication analysis was conducted by using CellChat package to identify dominant cell subsets.The FindAllMarker function was used to screen differentially expressed genes(DEGs)between the dominant cell subpopulation and other cell subpopulations,and its protein-protein interaction(PPI)network was constructed.The DEGs ranked in the top five of the Degree algorithm were taken as key genes.Then,the key genes were matched and mined with the cell communication network analyzed by CellChat to obtain the ligand-receptor pairs(L-R)and the signal pathways mediated by the key genes,and the results were visualized.At the same time,the atherosclerosis mouse model was constructed and RT-PCR was used to detect the expression of key genes in carotid atherosclerosis lesions.Results·A total of 11 cell subsets were identified in CA lesions,including smooth muscle cells,endothelial cells,macrophages,monocytes,etc.Cell communication results showed that CellChat detected 70 significant L-R and 26 related signal pathways in 11 cell subsets.Smooth muscle cell was the dominant cell subgroup with the most significant interaction frequency and intensity with other cell subgroups in the active state of communication.The results of DEGs screening showed that there were 206 DEGs between smooth muscle cell subsets and other cell subsets,among which ITGB2,PTPRC,CCL2,DCN and IGF1 were identified as key genes.The results of cell communication mediated by key genes showed that CCL2 and ACKR1 formed L-R and participated in the communication network between smooth muscle cells and endothelial cells through mediating CCL signaling pathway.ITGB2 formed receptor complexes with ITGAM and ITGAX respectively,and then formed L-R with C3 to mediate the complement signal pathway,participating in the communication network among smooth muscle cells,macrophages and monocytes.The validation results of hub genes in animal experiments were consistent with the results of bioinformatics analysis.Conclusion·Smooth muscle cells are the dominant cells in the pathological process of CA,and have extensive communication networks with other cells.They can construct cellular communication networks with endothelial cells,macrophages and monocytes through CCL and complement signaling pathways mediated by CCL2-ACKR1,C3-(ITGAM+ITGB2)and C3-(ITGAX+ITGB2).

Application of Single Cell RNA Sequencing in Glioblastoma Research / 华中科技大学学报(医学版)

Glioblastoma is the most common primary malignant tumor of brain in adults.Although great efforts have been made to improve prognosis in recent years,the median survival is still less than 20 months,and less than 5％of patients survive longer than 20 months.The standard treatment is maximum surgical excision combined with radiotherapy and temozolomide chemotherapy.Single cell RNA sequencing(scRNA-seq)technology accurately analyzes each unique cell,enabling us to better understand the heterogeneity of tumors,the evolution process of tumor cells,the special functions of various types of cells in the immune microenvironment,and the interactions between cells,thus providing new ideas for personalized clinical therapy.This review focuses on the application of scRNA-seq in the study of glioblastoma heterogeneity,tumor immune microenvironment,cell communication and treatment.

Single-cell RNA sequencing and the pathogenesis of intervertebral disc degeneration / 中国组织工程研究

BACKGROUND:Intervertebral disc degeneration is clinically considered to be the main cause of low back pain,but due to the unclear pathogenesis of intervertebral disc degeneration,there is still a lack of effective means to delay the progression of the disease.Single-cell RNA sequencing technology can amplify and sequence mRNA at the single-cell level,reveal the gene expression intensity of a single cell,discover different cell subsets in tissues according to the heterogeneity of cells,study the pathogenesis of intervertebral disc degeneration at the molecular level,and provide a new theoretical basis for its early diagnosis and treatment. OBJECTIVE:To introduce the basic principles of single-cell RNA sequencing technology and review the research progress of single-cell RNA sequencing technology in intervertebral disc degeneration in recent years. METHODS:A computer was used to search PubMed,Web of Science,CNKI and WanFang databases for the literature published from 2012 to 2022.Key words were"single-cell RNA sequencing,intervertebral disc degeneration,sequencing Technology"in Chinese and English.Duplicate,poor-quality and irrelevant articles were excluded;a total of 70 articles were eventually included. RESULTS AND CONCLUSION:(1)We identified new cell subsets such as homeostatic chondrocytes,hypertrophy chondrocyte-like nucleus pulposus cells and fibrous nucleus pulposus cells,identified the marker genes and transcription factors of these cell subsets,and described the functions,differentiation paths and cell fate of these cell subsets during the development and progression of intervertebral disc degeneration,and proposed the concept of progenitor nucleus pulposus cells.A cell subpopulation with progenitor nucleus pulposus cells properties was identified and its effectiveness in treating intervertebral disc degeneration was verified in mice.(2)Fibro chondrocyte-like annulus fibrosus cells and annulus fibrosus stem cells with both cartilage and fiber properties were identified,and a new type of composite hydrogel was prepared by combining fibrous cartilage inducers silk fibroin and hyaluronic acid in vitro.Experiments in mice demonstrated that this hydrogel could repair both annulus fibrosus tissue and cartilage matrix,and was remarkably effective in the treatment of intervertebral disc degeneration.(3)Regulatory chondrocytes were found in endplate cartilage.Two distinct fates in the progression of intervertebral disc degeneration were analyzed and the differential genes in the two fates were identified.Intercellular communication analysis indicated that regulatory chondrocytes interact with endothelial cells to promote angiogenesis.(4)Immune cells such as macrophages,T cells,myeloid progenitor cells and neutrophils were identified in the degenerated intervertebral disc tissues,demonstrating the existence of immune response during intervertebral disc degeneration.It was found that apolipoprotein induced the polarization of macrophages M1 and M2 subtypes,and this polarization process affected the activity of progenitor nucleus pulposus cells by amplifying the inflammatory response through the MIF signaling pathway.

Single-cell RNA sequencing reveals the heterogeneity of astrocytes / 中国组织工程研究

BACKGROUND:Astrocytes are the most abundant cells in the central nervous system,and various subsets of astrocytes are heterogeneous,performing a variety of special functions.Single-cell RNA sequencing(scRNA-seq)technology developed in recent years has extended our understanding of astrocyte heterogeneity from the perspective of transcriptome profiling. OBJECTIVE:To summarize the heterogeneity of scRNA-seq technology in different time and space,and pathological states and expand our knowledge of astrocyte heterogeneity on both molecular and functional levels. METHODS:The relevant articles on astrocyte heterogeneity and scRNA-seq were searched on PubMed,Elsevier,and CNKI databases.The search terms were"astrocytes,scRNA-seq,heterogeneity,Alzheimer disease,spinal cord injury,multiple sclerosis"in Chinese and English.Finally,74 articles were selected for viewing after screening according to inclusion criteria. RESULTS AND CONCLUSION:scRNA-seq studies related to the heterogeneity of astrocytes have shown that astrocyte is significantly heterogeneous across four aspects:species,developmental stage,central nervous system region,and pathological state.(1)Unique expression of certain genes occurs in astrocytes of different species,and the discovery of species-specific genes is beneficial for the translation of clinical studies.(2)During astrocyte development,differential gene expression emerged in the cellular subtypes identified at each stage,which further refined the cellular lineage of astrocytes and laid the foundation for the study of astrocyte developmental trajectories and mechanisms.(3)The discovery of differential gene expression allows regional localization of different astrocyte subpopulations and assists in the diagnosis and treatment of neurological diseases.(4)Astrocyte heterogeneity revealed by scRNA-seq can provide specific markers at the time of disease diagnosis and identify potential therapeutic targets.(5)The heterogeneity of astrocytes exists in many aspects,interacts with each other and is complex.The mechanisms of its generation,maintenance and transformation remain unclear.At present,molecular research on the single-cell level is still lacking.Linking transcriptionally defined astrocyte subpopulations to cellular activity,behavior and disease markers in real time remains one of the great challenges in the field.

Single-cell RNA sequencing-based research progress analysis of microglia in diabetic retinopathy / 中华眼底病杂志

Diabetic retinopathy (DR) is one of the main causes of vision loss and irreversible blindness in the working-age population, closely regarded as the destruction of the retinal neurovascular unit (NVU). As an important component of the NVU, retinal microglia (RMG) plays a vital role in the progression of DR. In recent years, single-cell RNA sequencing (scRNA-seq) technology has emerged as an important tool in transcriptomic analysis. This latest method reveals the heterogeneity and complexity of RNA transcriptional profiles within individual cells, as well as the composition of different cell types and functions. Utilizing scRNA-seq technology, researchers have further revealed the role of RMG in the occurrence and development of DR, discovering phenotypic heterogeneity, regional heterogeneity, and cell-to-cell communication in RMG. It is anticipated that in the future, more omics technologies and multi-omics correlation analysis methods will be applied to DR and even other ophthalmic diseases, exploring potential diagnostic and therapeutic targets, providing different perspectives for the clinical diagnosis, treatment, and scientific research of DR, and truly promoting clinical translation through technological innovation, thereby benefiting patients with DR diseases.

Research progress of single-cell RNA sequencing in the immune microenvironment analysis of non-small cell lung cancer / 中国胸心血管外科临床杂志

@#Non-small cell lung cancer (NSCLC) is one of the most common types of cancer in the world and is an important cause for cancer death. Although the application of immunotherapy in recent years has greatly improved the prognosis of NSCLC, there are still huge challenges in the treatment of NSCLC. The immune microenvironment plays an important role in the process of NSCLC development, infiltration and metastasis, and they can interact and influence each other, forming a vicious circle. Notably, single-cell RNA sequencing enables high-resolution analysis of individual cells and is of great value in revealing cell types, cell evolution trajectories, molecular mechanisms of cell differentiation, and intercellular regulation within the immune microenvironment. Single-cell RNA sequencing is expected to uncover more promising immunotherapies. This article reviews the important researches and latest achievements of single-cell RNA sequencing in the immune microenvironment of NSCLC, and aims to explore the significance of applying single-cell RNA sequencing to analyze the immune microenvironment of NSCLC.

Current status and progress of single cell RNA sequencing in the cellular mechanisms of diabetic retinopathy / 国际眼科杂志(Guoji Yanke Zazhi)

Diabetic retinopathy(DR)is one of the most common retinal complications of diabetes could cause irreversible loss of central vision in the working-age population. Current studies showed that systemic risk factors, inflammatory response, and oxidative stress played a central role in the development of DR. Although traditional sequencing methods have provided valuable insights into the pathogenesis of DR, offering crucial guidance for clinical diagnosis and treatment, they still possess certain limitations. In recent years, the emerging single-cell RNA sequencing technology(scRNA-seq)has enabled precise analysis of mRNA transcriptomes at the single-cell level. This technique accurately identifies novel cell subtypes in retinal diseases, detects rare cells, and reveals intercellular heterogeneity. It contributes to elucidating the pathogenesis and development of retinal diseases, and facilitates exploration of gene regulatory relationships associated with these disorders to provide valuable insights for future precision medicine. This article reviews the technology of single-cell sequencing and its application in DR research. It also explores the mechanisms of different types of cells associated with DR, aiming to enhance the utilization of scRNA-seq in DR research and identify potential therapeutic targets to improve clinical diagnosis and treatment of DR.

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.

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.

Single-cell analysis of cellular heterogeneity and interactions in the ischemia-reperfusion injured mouse intestine / 药物分析学报

Nine major cell populations among 46,716 cells were identified in mouse intestinal ischemia-reperfusion(Ⅱ/R)injury by single-cell RNA sequencing.For enterocyte cells,11 subclusters were found,in which enterocyte cluster 1(EC1),enterocyte cluster 3(EC3),and enterocyte cluster 8(EC8)were newly discovered cells in ischemia 45 min/reperfusion 720 min(I 45 min/R 720 min)group.EC1 and EC3 played roles in digestion and absorption,and EC8 played a role in cell junctions.For TA cells,after ischemia 45 min/reperfusion 90 min(I 45 min/R 90 min),many TA cells at the stage of proliferation were identified.For Paneth cells,Paneth cluster 3 was observed in the resting state of normal jejunum.After I45 min/R 90 min,three new subsets were found,in which Paneth cluster 1 had good antigen presentation activity.The main functions of goblet cells were to synthesize and secrete mucus,and a novel subcluster(goblet cluster 5)with highly proliferative ability was discovered in I 45 min/R 90 min group.As a major part of immune system,the changes in T cells with important roles were clarified.Notably,enterocyte cells secreted Guca2b to interact with Gucy2c receptor on the membranes of stem cells,TA cells,Paneth cells,and goblet cells to elicit intercellular communication.One marker known as glutathione S-transferase mu 3(GSTM3)affected intestinal mucosal barrier function by adjusting mitogen-activated protein kinases(MAPK)signaling during Ⅱ/R injury.The data on the heterogeneity of intestinal cells,cellular communication and the mechanism of GSTM3 provide a cellular basis for treating Ⅱ/R injury.

Single-cell transcriptome analysis reveals the regulatory effects of artesunate on splenic immune cells in polymicrobial sepsis / 药物分析学报

Sepsis is characterized by a severe and life-threatening host immune response to polymicrobial infection accompanied by organ dysfunction.Studies on the therapeutic effect and mechanism of immunomod-ulatory drugs on the sepsis-induced hyperinflammatory or immunosuppression states of various im-mune cells remain limited.This study aimed to investigate the protective effects and underlying mechanism of artesunate(ART)on the splenic microenvironment of cecal ligation and puncture-induced sepsis model mice using single-cell RNA sequencing(scRNA-seq)and experimental validations.The scRNA-seq analysis revealed that ART inhibited the activation of pro-inflammatory macrophages recruited during sepsis.ART could restore neutrophils'chemotaxis and immune function in the septic spleen.It inhibited the activation of T regulatory cells but promoted the cytotoxic function of natural killer cells during sepsis.ART also promoted the differentiation and activity of splenic B cells in mice with sepsis.These results indicated that ART could alleviate the inflammatory and/or immunosuppressive states of various immune cells involved in sepsis to balance the immune homeostasis within the host.Overall,this study provided a comprehensive investigation of the regulatory effect of ART on the splenic microenvironment in sepsis,thus contributing to the application of ART as adjunctive therapy for the clinical treatment of sepsis.

Single-cell RNA sequencing reveals the dynamics of hepatic non-parenchymal cells in autoprotection against acetaminophen-induced hepatotoxicity / 药物分析学报

Gaining a better understanding of autoprotection against drug-induced liver injury(DILI)may provide new strategies for its prevention and therapy.However,little is known about the underlying mechanisms of this phenomenon.We used single-cell RNA sequencing to characterize the dynamics and functions of hepatic non-parenchymal cells(NPCs)in autoprotection against DILI,using acetaminophen(APAP)as a model drug.Autoprotection was modeled through pretreatment with a mildly hepatotoxic dose of APAP in mice,followed by a higher dose in a secondary challenge.NPC subsets and dynamic changes were identified in the APAP(hepatotoxicity-sensitive)and APAP-resistant(hepatotoxicity-resistant)groups.A chemokine(C-C motif)ligand 2+endothelial cell subset almost disappeared in the APAP-resistant group,and an R-spondin 3+endothelial cell subset promoted hepatocyte proliferation and played an important role in APAP autoprotection.Moreover,the dendritic cell subset DC-3 may protect the liver from APAP hepatotoxicity by inducing low reactivity and suppressing the autoimmune response and occurrence of inflammation.DC-3 cells also promoted angiogenesis through crosstalk with endothelial cells via vascular endothelial growth factor-associated ligand-receptor pairs and facilitated liver tissue repair in the APAP-resistant group.In addition,the natural killer cell subsets NK-3 and NK-4 and the Sca-1-CD62L+natural killer T cell subset may promote autoprotection through interferon-y-dependent pathways.Furthermore,macrophage and neutrophil subpopulations with anti-inflammatory phenotypes promoted tolerance to APAP hepatotoxicity.Overall,this study reveals the dynamics of NPCs in the resistance to APAP hepatotoxicity and provides novel insights into the mechanism of autoprotection against DILI at a high resolution.

Application research progress of single cell RNA-sequencing technology in neurodegenerative diseases / 中国比较医学杂志

Neurodegenerative diseases(NDs)are closely related to the central nervous system and characterized by morphological abnormalities and progressive loss of function in specific neuron groups.The main NDs include Alzheimer's disease,Parkinson's disease,amyotrophic lateral sclerosis,multiple sclerosis and Huntington's disease.However,no direct therapies for NDs exist.In recent years,single cell RNA-sequencing(scRNA-seq)has been widely used in various NDs.The pathogenesis of NDs is closely related to morphology of immune cells,and the pathogenesis mainly involves mitochondrial function,glucose metabolism,inflammation,and synaptic transmission.Induced pluripotent stem cells are a potential therapy for NDs.Ultimately,we review the application of scRNA-seq to various NDs and provide a reference for prevention and treatment of NDs.

A single-nucleus transcriptomic atlas of primate testicular aging reveals exhaustion of the spermatogonial stem cell reservoir and loss of Sertoli cell homeostasis

The testis is pivotal for male reproduction, and its progressive functional decline in aging is associated with infertility. However, the regulatory mechanism underlying primate testicular aging remains largely elusive. Here, we resolve the aging-related cellular and molecular alterations of primate testicular aging by establishing a single-nucleus transcriptomic atlas. Gene-expression patterns along the spermatogenesis trajectory revealed molecular programs associated with attrition of spermatogonial stem cell reservoir, disturbed meiosis and impaired spermiogenesis along the sequential continuum. Remarkably, Sertoli cell was identified as the cell type most susceptible to aging, given its deeply perturbed age-associated transcriptional profiles. Concomitantly, downregulation of the transcription factor Wilms' Tumor 1 (WT1), essential for Sertoli cell homeostasis, was associated with accelerated cellular senescence, disrupted tight junctions, and a compromised cell identity signature, which altogether may help create a hostile microenvironment for spermatogenesis. Collectively, our study depicts in-depth transcriptomic traits of non-human primate (NHP) testicular aging at single-cell resolution, providing potential diagnostic biomarkers and targets for therapeutic interventions against testicular aging and age-related male reproductive diseases.

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.

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.

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.

High-throughput transcriptional profiling of perturbations by Panax ginseng saponins and Panax notoginseng saponins using TCM-seq / 药物分析学报

Panax ginseng(PG)and Panax notoginseng(PN)are highly valuable Chinese medicines(CM).Although both CMs have similar active constituents,their clinical applications are clearly different.Over the past decade,RNA sequencing(RNA-seq)analysis has been employed to investigate the molecular mechanisms of extracts or monomers.However,owing to the limited number of samples in standard RNA-seq,few studies have systematically compared the effects of PG and PN spanning multiple conditions at the transcriptomic level.Here,we developed an approach that simultaneously profiles transcriptome changes for multiplexed samples using RNA-seq(TCM-seq),a high-throughput,low-cost workflow to molecularly evaluate CM perturbations.A species-mixing experiment was conducted to illustrate the accuracy of sample multiplexing in TCM-seq.Transcriptomes from repeated samples were used to verify the robustness of TCM-seq.We then focused on the primary active components,Panax notoginseng sa-ponins(PNS)and Panax ginseng saponins(PGS)extracted from PN and PG,respectively.We also char-acterized the transcriptome changes of 10 cell lines,treated with four different doses of PNS and PGS,using TCM-seq to compare the differences in their perturbing effects on genes,functional pathways,gene modules,and molecular networks.The results of transcriptional data analysis showed that the tran-scriptional patterns of various cell lines were significantly distinct.PGS exhibited a stronger regulatory effect on genes involved in cardiovascular disease,whereas PNS resulted in a greater coagulation effect on vascular endothelial cells.This study proposes a paradigm to comprehensively explore the differences in mechanisms of action between CMs based on transcriptome readouts.

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.

Changes in metabolic capacity and gene expression of brown adipose tissue in the first and third trimester of pregnancy / 中华内分泌代谢杂志

Objective:To explore gene expression and metabolic capacity changes of brown adipose tissue(BAT)during different gestation periods.Methods:A normal pregnancy model was established using C57BL/6J mice, while infertile mice of the same age were served as the control group. The morphological alteration of BAT during pregnancy as well as the gene expression of uncoupling protein 1(UCP1) and other fat browning and mitochondrial marker genes were detected. Moreover, BATs from early and late gestation were selected to screen differentially expressed genes in relation to pregnancy progressing by RNA sequencing(RNA-seq), and gene ontology(GO) and Kyoto gene and gene sequencing(KEGG)were performed.Results:With pregnancy progressing, the size of BAT lipid droplets was substantially enlarged, UCP1 protein expression was decreased( P<0.01), and the fat browning marker genes(Ucp1, Dio2, and Pgc1α)and the mitochondrial marker gene CytC were downregulated( P<0.001). Additionally, a total of 1 298 distinct genes were identified by RNA-seq, 906 of which were upregulated and 392 were downregulated at later stage of pregnancy. GO and KEGG analyses revealed that the differentially expressed genes were mainly enriched in bioregulatory functional pathways such as lipid metabolism, sex steroid hormones, and inflammatory factors. Conclusion:BAT in mice showed larger lipid droplets and reduced thermogenic and metabolic capacity during late gestation, and BAT gene expression was significantly different in different periods of gestation, so reduced metabolic capacity of BAT may contribute to metabolic abnormality during pregnancy.