• 제목/요약/키워드: Single cell analysis/methods

검색결과 206건 처리시간 0.025초

Transcriptomic Analysis of Cellular Senescence: One Step Closer to Senescence Atlas

  • Kim, Sohee;Kim, Chuna
    • Molecules and Cells
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    • 제44권3호
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    • pp.136-145
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    • 2021
  • Senescent cells that gradually accumulate during aging are one of the leading causes of aging. While senolytics can improve aging in humans as well as mice by specifically eliminating senescent cells, the effect of the senolytics varies in different cell types, suggesting variations in senescence. Various factors can induce cellular senescence, and the rate of accumulation of senescent cells differ depending on the organ. In addition, since the heterogeneity is due to the spatiotemporal context of senescent cells, in vivo studies are needed to increase the understanding of senescent cells. Since current methods are often unable to distinguish senescent cells from other cells, efforts are being made to find markers commonly expressed in senescent cells using bulk RNA-sequencing. Moreover, single-cell RNA (scRNA) sequencing, which analyzes the transcripts of each cell, has been utilized to understand the in vivo characteristics of the rare senescent cells. Recently, transcriptomic cell atlases for each organ using this technology have been published in various species. Novel senescent cells that do not express previously established marker genes have been discovered in some organs. However, there is still insufficient information on senescent cells due to the limited throughput of the scRNA sequencing technology. Therefore, it is necessary to improve the throughput of the scRNA sequencing technology or develop a way to enrich the rare senescent cells. The in vivo senescent cell atlas that is established using rapidly developing single-cell technologies will contribute to the precise rejuvenation by specifically removing senescent cells in each tissue and individual.

Fabrication and Characterization of Thermally Actuated Bimorph Probe for Living Cell Measurements with Experimental and Numerical Analysis

  • Cho Young-Hak;Kang Beom-Joon;Hong Seok-Kwan;Kang Jeong-Jin
    • Journal of Mechanical Science and Technology
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    • 제20권3호
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    • pp.297-309
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    • 2006
  • This paper deals with a novel structure for single-cell characterization which makes use of bimorph micro thermal actuators combined with electrical sensor device and integrated microfluidic channel. The goal for this device is to capture and characterize individual biocell. Quantitative and qualitative characteristics of bimorph thermal actuator were analyzed with finite element analysis methods. Furthermore, optimization for the dimension of cantilevers and integrated parallel probe systems with microfluidic channels is able to be realized through the virtual simulation for actuation and the practical fabrication of prototype of probes. The experimental value of probe deflection was in accordance with the simulated one.

Electrophoretic Tissue Clearing and Labeling Methods for Volume Imaging of Whole Organs

  • Kim, Dai Hyun;Ahn, Hyo Hyun;Sun, Woong;Rhyu, Im Joo
    • Applied Microscopy
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    • 제46권3호
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    • pp.134-139
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    • 2016
  • Detailed structural and molecular imaging of intact organs has incurred academic interest because the associated technique is expected to provide innovative information for biological investigation and pathological diagnosis. The conventional methods for volume imaging include reconstruction of images obtained from serially sectioned tissues. This approach requires intense manual work which involves inevitable uncertainty and much time to assemble the whole image of a target organ. Recently, effective tissue clearing techniques including CLARITY and ACT-PRESTO have been reported that enables visualization of molecularly labeled structures within intact organs in three dimensions. The central principle of the methods is transformation of intact tissue into an optically transpicuous and macromolecule permeable state without loss of intrinsic structural integrity. The rapidly evolving protocols enable morphological analysis and molecular labeling of normal and pathological characteristics in large assembled biological systems with single-cell resolution. The deep tissue volume imaging will provide fundamental information about mutual interaction among adjacent structures such as connectivity of neural circuits; meso-connectome and clinically significant structural alterations according to pathologic mechanisms or treatment procedures.

Single-molecule fluorescence in situ hybridization: Quantitative imaging of single RNA molecules

  • Kwon, Sunjong
    • BMB Reports
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    • 제46권2호
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    • pp.65-72
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    • 2013
  • In situ detection of RNAs is becoming increasingly important for analysis of gene expression within and between intact cells in tissues. International genomics efforts are now cataloging patterns of RNA transcription that play roles in cell function, differentiation, and disease formation, and they are demon-strating the importance of coding and noncoding RNA transcripts in these processes. However, these techniques typically provide ensemble averages of transcription across many cells. In situ hybridization-based analysis methods complement these studies by providing information about how expression levels change between cells within normal and diseased tissues, and they provide information about the localization of transcripts within cells, which is important in understanding mechanisms of gene regulation. Multi-color, single-molecule fluorescence in situ hybridization (smFISH) is particularly useful since it enables analysis of several different transcripts simultaneously. Combining smFISH with immunofluorescent protein detection provides additional information about the association between transcription level, cellular localization, and protein expression in individual cells.

A simple and rapid method for detection of single nucleotide variants using tailed primer and HRM analysis

  • Hyeonguk Baek;Inchul, Choi
    • Journal of Animal Reproduction and Biotechnology
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    • 제38권4호
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    • pp.209-214
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    • 2023
  • Background: Single nucleotide polymorphisms (SNPs) are widely used genetic markers with applications in human disease diagnostics, animal breeding, and evolutionary studies, but existing genotyping methods can be labor-intensive and costly. The aim of this study is to develop a simple and rapid method for identification of a single nucleotide change. Methods: A modified Polymerase Chain Reaction Amplification of Multiple Specific Alleles (PAMSA) and high resolution melt (HRM) analysis was performed to discriminate a bovine polymorphism in the NCAPG gene (rs109570900, 1326T > G). Results: The inclusion of tails in the primers enabled allele discrimination based on PCR product lengths, detected through agarose gel electrophoresis, successfully determining various genotypes, albeit with some time and labor intensity due to the use of relatively costly high-resolution agarose gels. Additionally, high-resolution melt (HRM) analysis with tailed primers effectively distinguished the GG genotype from the TT genotype in bovine muscle cell lines, offering a reliable way to distinguish SNP polymorphisms without the need for time-consuming AS-PCR. Conclusions: Our experiments demonstrated the importance of incorporating unique mismatched bases in the allele-specific primers to prevent cross-amplification by fragmented primers. This efficient and cost-effective method, as presented here, enables genotyping laboratories to analyze SNPs using standard real-time PCR.

Single-Cell RNA Sequencing of Bone Marrow Mesenchymal Stem Cells from the Elderly People

  • Dezhou Zhu;Jie Gao;Chengxuan Tang;Zheng Xu;Tiansheng Sun
    • International Journal of Stem Cells
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    • 제15권2호
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    • pp.173-182
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    • 2022
  • Background and Objectives: Bone marrow mesenchymal stem cells (BMSCs) show considerable promise in regenerative medicine. Many studies demonstrated that BMSCs cultured in vitro were highly heterogeneous and composed of diverse cell subpopulations, which may be the basis of their multiple biological characteristics. However, the exact cell subpopulations that make up BMSCs are still unknown. Methods and Results: In this study, we used single-cell RNA sequencing (scRNA-Seq) to divide 6,514 BMSCs into three clusters. The number and corresponding proportion of cells in clusters 1 to 3 were 3,766 (57.81%), 1,720 (26.40%), and 1,028 (15.78%). The gene expression profile and function of the cells in the same cluster were similar. The vast majority of cells expressed the markers defining BMSCs by flow cytometry and gene expression analysis. Each cluster had at least 20 differentially expressed genes (DEGs). We conducted Gene Ontology enrichment analysis on the top 20 DEGs of each cluster and found that the three clusters had different functions, which were related to self-renewal, multilineage differentiation and cytokine secretion, respectively. In addition, the function of the top 20 DEGs of each cluster was checked by the National Center for Biotechnology Information gene database to further verify our hypothesis. Conclusions: This study indicated that scRNA-Seq can be used to divide BMSCs into different subpopulations, demonstrating the heterogeneity of BMSCs.

Dissection of Cellular Communication between Human Primary Osteoblasts and Bone Marrow Mesenchymal Stem Cells in Osteoarthritis at Single-Cell Resolution

  • Ying Liu;Yan Chen;Xiao-Hua Li;Chong Cao;Hui-Xi Zhang;Cui Zhou;Yu Chen;Yun Gong;Jun-Xiao Yang;Liang Cheng;Xiang-Ding Chen;Hui Shen;Hong-Mei Xiao;Li-Jun Tan;Hong-Wen Deng
    • International Journal of Stem Cells
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    • 제16권3호
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    • pp.342-355
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    • 2023
  • Background and Objectives: Osteoblasts are derived from bone marrow mesenchymal stem cells (BMMSCs) and play important role in bone remodeling. While our previous studies have investigated the cell subtypes and heterogeneity in osteoblasts and BMMSCs separately, cell-to-cell communications between osteoblasts and BMMSCs in vivo in humans have not been characterized. The aim of this study was to investigate the cellular communication between human primary osteoblasts and bone marrow mesenchymal stem cells. Methods and Results: To investigate the cell-to-cell communications between osteoblasts and BMMSCs and identify new cell subtypes, we performed a systematic integration analysis with our single-cell RNA sequencing (scRNA-seq) transcriptomes data from BMMSCs and osteoblasts. We successfully identified a novel preosteoblasts subtype which highly expressed ATF3, CCL2, CXCL2 and IRF1. Biological functional annotations of the transcriptomes suggested that the novel preosteoblasts subtype may inhibit osteoblasts differentiation, maintain cells to a less differentiated status and recruit osteoclasts. Ligand-receptor interaction analysis showed strong interaction between mature osteoblasts and BMMSCs. Meanwhile, we found FZD1 was highly expressed in BMMSCs of osteogenic differentiation direction. WIF1 and SFRP4, which were highly expressed in mature osteoblasts were reported to inhibit osteogenic differentiation. We speculated that WIF1 and sFRP4 expressed in mature osteoblasts inhibited the binding of FZD1 to Wnt ligand in BMMSCs, thereby further inhibiting osteogenic differentiation of BMMSCs. Conclusions: Our study provided a more systematic and comprehensive understanding of the heterogeneity of osteogenic cells. At the single cell level, this study provided insights into the cell-to-cell communications between BMMSCs and osteoblasts and mature osteoblasts may mediate negative feedback regulation of osteogenesis process.

Experimental study trends on the prevention and treatment effects of herbal medicine for gastroesophageal reflux disease (GERD) - based on Pubmed (천연물의 위식도역류질환 예방, 치료 효과에 대한 실험연구 현황 – Pubmed를 중심으로)

  • YongBin Kim;Young-Sik Kim
    • Herbal Formula Science
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    • 제31권4호
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    • pp.389-413
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    • 2023
  • Objectives : This study aimed to review the current trends in experimental studies on the use of natural products for treatment of gastroesophageal reflux disease (GERD). Methods : Experimental studies assessing the efficacy of natural products against GERD were searched on PubMed. Articles were selected based on predefined inclusion and exclusion criteria and then analyzed for experimental methods, interventions, and result analysis techniques. Results : A total 37 studies were included in this review. Predominantly, in vivo experiments were conducted to induce GERD through surgery, involving the ligation of the pylorus and the transitional junction between the corpus and the forestomach using 7-week-old male Sprague-Dawley rats. The acute induction model, sacrificing animals after a single administration following GERD induction, was mainly used.The utilization of cell experiments was relatively infrequent, with a focus on assessing antioxidant and anti-inflammatory effects via the treatment of the RAW 264.7 cell line with lipopolysaccharides treatment. Glycyrrhizae Radix et Rhizoma, Pinelliae Tuber, Ginseng Radix and Zingiberis Rhizoma were used as single ingredients, and herbal formula, STW-5 (iberogast), Rikkunshito (六君子湯), Banhasasim-tang (半夏瀉心湯), and Hewei Jiangni granule (和胃降逆湯) were used. Outcome analysis methods encompassed Macroscopic evaluation, esophageal function assessment, blood biomarker analysis, histological examination, protein analysis, gene expression analysis, and gastric juice analysis. Proton pump inhibitors were predominantly employed as positive controls. Conclusions : This study revealed the current trends in non-clinical research evaluating natural products for GERD. Based on the results of this study, we expect that non-clinical research on clinically effective natural products will be revitalized.

Importance of the Cell Block Technique in Diagnosing Patients with Non-Small Cell Carcinoma Accompanied by Pleural Effusion

  • Ugurluoglu, Ceyhan;Kurtipek, Ercan;Unlu, Yasar;Esme, Hidir;Duzgun, Nuri
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권7호
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    • pp.3057-3060
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    • 2015
  • Background: Cytological examination of pleural effusions is very important in the diagnosis of malignant lesions. Thoracentesis is the first investigation to be performed in a patient with pleural effusion. In this study, we aimed to compare traditional with cell block methods for diagnosis of lung disease accompanied by pleural effusion. Materials and Methods: A total of 194 patients with exudative pleural effusions were included. Ten mililiters of fresh pleural fluid were obtained by thoracentesis from all patients in the initial evaluation. The samples gathered were divided to two equal parts, one for conventional cytological analysis and the other for analysis with the cell block technique. In cytology, using conventional diagnostic criteria cases were divided into 3 categories, benign, malignant and undetermined. The cell block sections were evaluated for the presence of single tumor cells, papillary or acinar patterns and staining with mucicarmine. In the cell block examination, in cases with sufficient cell counts histopathological diagnosis was performed. Results: Of the total undergoing conventional cytological analyses, 154 (79.4%)were reported as benign, 33 (17%) as malignant and 7 (3.6%) as suspicious of malignancy. With the cell block method the results were 147 (75.8%) benign, 12 (6.2%) metastatic, 4 (2.1%) squamous cell carcinoma, 18 (9.3%) adenocarcinoma, 5 (2.6%) large cell carcinoma, 2 (1%) mesothelioma, 3 (1.5%) small cell carcinoma, and 3 (1.5%) lymphoma. Conclusions: Our study confirmed that the cell block method increases the diagnostic yield with exudative pleural effusions accompanying lung cancer.

Multiparameter Flow Cytometry: Advances in High Resolution Analysis

  • O'Donnell, Erika A.;Ernst, David N.;Hingorani, Ravi
    • IMMUNE NETWORK
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    • 제13권2호
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    • pp.43-54
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    • 2013
  • Over the past 40 years, flow cytometry has emerged as a leading, application-rich technology that supports high-resolution characterization of individual cells which function in complex cellular networks such as the immune system. This brief overview highlights advances in multiparameter flow cytometric technologies and reagent applications for characterization and functional analysis of cells modulating the immune network. These advances significantly support highthroughput and high-content analyses and enable an integrated understanding of the cellular and molecular interactions that underlie complex biological systems.