Application of CRISPR-Cas9 to interrogate novel gene functions in cutaneous melanoma

Melanoma accounts for 3% of skin neoplasms and is the leading cause of death from skin disorders worldwide. The high mortality rate associated with this disease stems from the high capacity of melanoma patients to develop metastases and treatment relapse with inhibitors of the MAPK signaling pathway (such as BRAF inhibitors), commonly used in melanoma therapy. Thus, the investigation of genes involved in the mechanisms of melanoma development is essential for new and more effective therapeutic strategies. Hence, we describe in this thesis two projects involving the genes SIN3B and IRF4 as possible biomarkers for cutaneous melanoma. Initially, through bioinformatics analyses performed by our group, an upregulation of SIN3B was found in metastatic melanomas. This result together with the understanding of SIN3B role in regulating gene expression and oncogenic transformation, prompted us to describe in this thesis some mechanisms by which SIN3B may influence melanoma development. We then sought to characterize the gene function using SIN3B-deleted cells, generated by the CRISPR-Cas9 methodology. Initially, we observed increased SIN3B expression in BRAF-mutant metastatic melanomas, where we noted that the long splicing variant of the gene (NM_001297595.1) was effectively prevalent in melanomas. Subsequently, we designed gRNAs between the exons 2 and 3 of the human SIN3B gene and engineered three knockout clones and three control clones (containing empty lentiCRISPRv2 plasmid) from different melanoma cell lines (SKMEL28, A2058, and A375). Through functional analyses, it was observed that the absence of the gene did not interfere in the proliferation of tumor cells; however, it led to a decrease in invasive properties. These results were verified by Boyden chamber assays and transcriptome analysis (total RNA sequencing of deleted cells), where a decrease in migration and motility pathways was observed. Additionally, a screening of synthetically lethal genes with SIN3B was performed with a genome wide CRISPR library. These results showed that USP7 and STK11 genes, which belong to the FoxO signaling pathway, were essential in SIN3B-depleted melanoma cells. Finally, through a collaborative project with the Wellcome Trust Sanger Institute, previous large-scale sequencing analyses demonstrated that deletion of the IRF4 gene was lethal for melanoma cells. Accordingly, we performed IRF4 silencing in vitro and noticed that the lack of IRF4 promotes cell death and apoptosis, independently of MYC and MITF, known in the literature to be downstream targets of this gene. Therefore, these data suggest that IRF4 plays a vital role in melanoma cell survival. Taken together, both works herein described in this thesis demonstrate how CRISPR-Cas9 can be applied to study the functions and mechanisms of genes involved in melanoma progression, collectively helping in the development of more effective therapeutic strategies for this tumor

O melanoma representa 3% dos tipos de neoplasias cutâneas e é a maior causa das mortes por distúrbios de pele no mundo. A alta taxa de mortalidade associada à essa doença advém da alta capacidade de pacientes com melanoma desenvolverem metástases, e apresentarem recidiva após tratamento com inibidores da via de sinalização MAPK (como da proteína BRAF), comumente utilizados no tratamento de pacientes metastáticos. Assim, a investigação de genes envolvidos nos mecanismos de desenvolvimento do melanoma é primordial para novas estratégias terapêuticas mais efetivas. Dessa forma, descrevemos no presente trabalho dois projetos envolvendo os genes SIN3B e IRF4 como possíveis biomarcadores para melanoma cutâneo. Em análises prévias de bioinformática realizados pelo nosso grupo, SIN3B foi identificado tendo maior expressão em melanomas metastáticos. Além disso, diversos estudos mostraram que o gene está envolvido na regulação da expressão gênica e transformação oncogênica. Dessa forma, descrevemos nessa tese alguns mecanismos pelos quais SIN3B pode influenciar no desenvolvimento do melanoma, através da caracterização funcional de células SIN3B-deletadas pela metodologia CRISPR-Cas9. Inicialmente, observamos aumento na expressão de SIN3B em melanomas metastáticos BRAF-mutados, onde notamos que a variante de splicing longa do gene (NM_001297595.1), era efetivamente prevalente em melanomas. Assim, desenhamos sequências de RNA guias entre os éxons 2 e 3 do gene SIN3B humano e, obtivemos três clones knockout e outros três clones controle (contendo plasmídeo vazio) em diferentes linhagens de melanoma (SKMEL28, A2058 e A375), para caracterização funcional. Observou-se que a ausência do gene não interferiu na proliferação das células tumorais, contudo, acarretou na diminuição de processos invasivos. Esses resultados foram averiguados através de ensaios em câmara de Boyden e análises de transcriptoma (sequenciamento de RNA total das células deletadas), onde notou-se diminuição das vias de migração e motilidade. Adicionalmente, um rastreamento de genes sinteticamente letais com SIN3B foi realizado com uma biblioteca de CRISPR capaz de silenciar todo o genoma. Esses resultados mostraram que os genes USP7 e STK11, ambos pertencentes à via de sinalização de FoxO, são essenciais nas células SIN3B deletadas. Por fim, através de um projeto colaborativo com o Wellcome Trust Sanger Institute, análises prévias de sequenciamento de larga escala demonstraram que a deleção do gene IRF4 era letal para células de melanoma. Dessa forma, realizamos o silenciamento de IRF4 in vitro e notamos que a ausência do gene promove morte celular e apoptose, independentemente de MYC e MITF, conhecidos na literatura por serem alvos downstream do gene. Portanto, esses dados sugerem que IRF4 tem um papel importante na sobrevivência de células de melanoma. Em conjunto, ambos trabalhos descritos nessa tese, demonstram como a metodologia CRISPR-Cas9 pode auxiliar no entendimento de processos importantes para a malignidade do melanoma e contribuir para estratégias terapêuticas mais efetivas para esse tumor

Secuenciación de próxima generación para la detección de patógenos en cirugía de cadera: experiencia y viabilidad diagnóstica en un centro de atención terciaria de la Argentina / Next generation sequencing for the detection of pathogens in hip surgery. Experience and diagnostic feasibility in a tertiary care center in Argentina

Introducción: El diagnóstico rápido y definitivo con identificación del patógeno es fundamental cuando hay una infección periprotésica. La secuenciación de próxima generación permite identificar el ADN en un germen determinado en poco tiempo. Hasta donde sabemos, no hay reportes sobre su empleo para el manejo de la infección periprotésica en Sudamérica. Nuestro objetivo fue demostrar la viabilidad diagnóstica de las muestras obtenidas de una serie de pacientes operados en Buenos Aires, Argentina, y analizadas con la técnica de secuenciación de próxima generación. materiales y métodos: Se analizó a una serie prospectiva de 20 pacientes sometidos a cirugía de revisión séptica y aséptica de cadera desde diciembre de 2019 hasta marzo de 2020. Se obtuvieron muestras intraoperatorias de líquido sinovial, tejido profundo y canal endomedular, que fueron enviadas para su análisis al laboratorio NexGen Microgen. Resultados: Se seleccionaron 17 pacientes, porque tenían una muestra apta para analizar. Los resultados se recibieron dentro de las 72 h de la cirugía. En un caso, el resultado de la secuenciación de próxima generación informó un germen distinto del identificado en los cultivos posoperatorios de partes blandas, esto permitió corregir la antibioticoterapia. En otro, esta técnica identificó Parabacteroides gordonii en una revisión aséptica, en otro, Morganella morganii, a partir de cultivos negativos en una revisión en un tiempo. Conclusión: Se demostró la viabilidad diagnóstica con la secuenciación de próxima generación, se pueden obtener resultados de microorganismos patógenos dentro de las 72 h posteriores a la cirugía en pacientes con infección periprotésica y cultivos negativos. Nivel de Evidencia: IV

Introduction: Early diagnosis of a periprosthetic joint infection (PJI) and identification of the pathogen are paramount. Next-generation sequencing (NGS) can identify the nucleic acids in a given germ in a short period. To our knowledge, there are no reports of its use in the management of PJI in South America. Our objective was to demonstrate the diagnostic feasibility of the NGS technique on the samples obtained from a series of patients operated on in Buenos Aires, Argentina. Materials and methods: A prospective series of 20 patients undergoing septic and aseptic hip revision surgery from December 2019 to March 2020 was analyzed. Intraoperative samples of synovial fluid, deep tissue, and intramedullary canal were obtained and sent to the NexGen Microgen laboratory (Texas, USA) for analysis. Results: Seventeen patients were finally eligible to present a sample suitable for analysis. In 100% of the samples, NGS results were obtained within 72 hours of surgery. In one case, the NGS result reported a germ different from the one identified in the postoperative soft tissue cultures, allowing antibiotic therapy to be corrected. In another case, NGS identified Parabacteroides gordonii in aseptic revision surgery. In another patient, the NGS identified Morganella morganii, in which conventional postoperative cultures were negative in single-stage revision surgery. Conclusion: In this study, we demonstrated the diagnostic feasibility of NGS, obtaining results within 72 hours immediately after surgery for pathogenic organisms in patients with PJI and negative cultures. Level of Evidence: IV

Type C botulism in dogs from rural properties located in Goiânia, Brazil

Botulism is a disease usually fatal, caused by the ingestion of neurotoxins produced by Clostridium botulinum. In dogs, intoxication is caused by the ingestion of botulinum toxin type C, and animals often recover spontaneously. The present study describes the occurrence of type C botulism in two dogs domiciled on neighboring rural properties in the municipality of Goiânia, state of Goiás, Brazil, probably associated with ingestion of decomposing bovine carcass. Upon clinical evaluation, the dogs were alert in the lateral decubitus position with ascending flaccid paralysis, absence of eyelid reflexes, and reduced muscle tone. Due to their worsening clinical symptoms, the animals died within 12 h and 3 days after supportive treatment. Botulinum toxin type C was identified, in the serum and feces of both dogs, by seroneutralization in mice with homologous monovalent antitoxin. The results of the high-throughput gene sequencing showed that the abundance of C. botulinum in the fecal microbiota of one of the affected dogs was low (0.53%). In this way, the present study highlights the need of sanitary practices related to the appropriate collection and disposal of bovine carcasses in rural areas since they represent a risk factor for the occurrence of botulism in dogs domiciled on rural properties.

Cancer biology deciphered by single-cell transcriptomic sequencing

Tumors are complex ecosystems in which heterogeneous cancer cells interact with their microenvironment composed of diverse immune, endothelial, and stromal cells. Cancer biology had been studied using bulk genomic and gene expression profiling, which however mask the cellular diversity and average the variability among individual molecular programs. Recent advances in single-cell transcriptomic sequencing have enabled a detailed dissection of tumor ecosystems and promoted our understanding of tumorigenesis at single-cell resolution. In the present review, we discuss the main topics of recent cancer studies that have implemented single-cell RNA sequencing (scRNA-seq). To study cancer cells, scRNA-seq has provided novel insights into the cancer stem-cell model, treatment resistance, and cancer metastasis. To study the tumor microenvironment, scRNA-seq has portrayed the diverse cell types and complex cellular states of both immune and non-immune cells interacting with cancer cells, with the promise to discover novel targets for future immunotherapy.

Application of single-cell transcriptome sequencing in mechanistic toxicology / 中华预防医学杂志

Traditional bulk RNA sequencing assesses the average expression level of genes in tissues rather than the differences in cellular responses. Accordingly, it is hard to differentiate sensitive responding cells, leading to inaccurate identification of toxicity pathways. Single-cell RNA sequencing (scRNA-seq) isolated single cells from tissue and subjected them to cell subtypes-specific transcriptome analysis. This technique in toxicological studies realizes the heterogeneous cellular responses in the tissue microenvironment upon chemical exposure. Thus it helps to identify sensitive responding cells and key molecular events, providing a powerful tool and a new perspective for exploring the mechanisms of toxicity and the modes of action. This review summarizes the development, principle, method, application and limitations of scRNA-seq in mechanistic toxicological researches, and discusses the prospect of multi-directional applications.

Investigation on the growth factor regulatory network of dermal fibroblasts in mouse full-thickness skin defect wounds based on single-cell RNA sequencing / 中华烧伤杂志

Objective: To explore the heterogeneity and growth factor regulatory network of dermal fibroblasts (dFbs) in mouse full-thickness skin defect wounds based on single-cell RNA sequencing. Methods: The experimental research methods were adopted. The normal skin tissue from 5 healthy 8-week-old male C57BL/6 mice (the same mouse age, sex, and strain below) was harvested, and the wound tissue of another 5 mice with full-thickness skin defect on the back was harvested on post injury day (PID) 7. The cell suspension was obtained by digesting the tissue with collagenase D and DNase Ⅰ, sequencing library was constructed using 10x Genomics platform, and single-cell RNA sequencing was performed by Illumina Novaseq6000 sequencer. The gene expression matrices of cells in the two kinds of tissue were obtained by analysis of Seurat 3.0 program of software R4.1.1, and two-dimensional tSNE plots classified by cell group, cell source, and gene labeling of major cells in skin were used for visual display. According to the existing literature and the CellMarker database searching, the expression of marker genes in the gene expression matrices of cells in the two kinds of tissue was analyzed, and each cell group was numbered and defined. The gene expression matrices and cell clustering information were introduced into CellChat 1.1.3 program of software R4.1.1 to analyze the intercellular communication in the two kinds of tissue and the intercellular communication involving vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), epidermal growth factor (EGF), and fibroblast growth factor (FGF) signal pathways in the wound tissue, the relative contribution of each pair of FGF subtypes and FGF receptor (FGFR) subtypes (hereinafter referred to as FGF ligand receptor pairs) to FGF signal network in the two kinds of tissue, and the intercellular communication in the signal pathway of FGF ligand receptor pairs with the top 2 relative contributions in the two kinds of tissue. The normal skin tissue from one healthy mouse was harvested, and the wound tissue of one mouse with full-thickness skin defect on the back was harvested on PID 7. The multiple immunofluorescence staining was performed to detect the expression and distribution of FGF7 protein and its co-localized expression with dipeptidyl peptidase 4 (DPP4), stem cell antigen 1 (SCA1), smooth muscle actin (SMA), and PDGF receptor α (PDGFRα) protein. Results: Both the normal skin tissue of healthy mice and the wound tissue of full-thickness skin defected mice on PID 7 contained 25 cell groups, but the numbers of cells in each cell group between the two kinds of tissue were different. Genes PDGFRα, platelet endothelial cell adhesion molecule 1, lymphatic endothelial hyaluronic acid receptor 1, receptor protein tyrosine phosphatase C, keratin 10, and keratin 79 all had distinct distributions on two-dimensional tSNE plots, indicating specific cell groups respectively. The 25 cell groups were numbered by C0-C24 and divided into 9 dFb subgroups and 16 non-dFb groups. dFb subgroups included C0 as interstitial progenitor cells, C5 as adipose precursor cells, and C13 as contractile muscle cells related fibroblasts, etc. Non-dFb group included C3 as neutrophils, C8 as T cells, and C18 as erythrocytes, etc. Compared with that of the normal skin tissue of healthy mice, the intercellular communication in the wound tissue of full-thickness skin defected mice on PID 7 was more and denser, and the top 3 cell groups in intercellular communication intensity were dFb subgroups C0, C1, and C2, of which all communicated with other cell groups in the wound tissue. In the wound tissue of full-thickness skin defected mice on PID 7, VEGF signals were mainly sent by the dFb subgroup C0 and received by vascular related cell groups C19 and C21, PDGF signals were mainly sent by peripheral cells C14 and received by multiple dFb subgroups, EGF signals were mainly sent by keratinocyte subgroups C9 and C11 and received by the dFb subgroup C0, and the main sender and receiver of FGF signals were the dFb subgroup C6. In the relative contribution rank of FGF ligand receptor pairs to FGF signal network in the normal skin tissue of healthy mice and the wound tissue of full-thickness skin defected mice on PID 7, FGF7-FGFR1 was the top 1, and FGF7-FGFR2 or FGF10-FGFR1 was in the second place, respectively; compared with those in the normal skin tissue, there was more intercellular communication in FGF7-FGFR1 signal pathway, while the intercellular communication in FGF7-FGFR2 and FGF10-FGFR1 signal pathways decreased slightly or did not change significantly in the wound tissue; the intercellular communication in FGF7-FGFR1 signal pathway in the wound tissue was stronger than that in FGF7-FGFR2 or FGF10-FGFR1 signal pathway; in the two kinds of tissue, FGF7 signal was mainly sent by dFb subgroups C0, C1, and C2, and received by dFb subgroups C6 and C7. Compared with that in the normal skin tissue of healthy mouse, the expression of FGF7 protein was higher in the wound tissue of full-thickness skin defected mouse on PID 7; in the normal skin tissue, FGF7 protein was mainly expressed in the skin interstitium and also expressed in the white adipose tissue near the dermis layer; in the two kinds of tissue, FGF7 protein was co-localized with DPP4 and SCA1 proteins and expressed in the skin interstitium, co-localized with PDGFRα protein and expressed in dFbs, but was not co-localized with SMA protein, with more co-localized expression of FGF7 in the wound tissue than that in the normal skin tissue. Conclusions: In the process of wound healing of mouse full-thickness skin defect wound, dFbs are highly heterogeneous, act as potential major secretory or receiving cell populations of a variety of growth factors, and have a close and complex relationship with the growth factor signal pathways. FGF7-FGFR1 signal pathway is the main FGF signal pathway in the process of wound healing, which targets and regulates multiple dFb subgroups.

Screening of Variants in the Transcript Profile of Eutopic Endometrium from Infertile Women with Endometriosis during the Implantation Window / Rastreio de variantes no perfil de tanscritos do endométrio eutópico de mulheres inférteis com endometriose durante a janela de implantação

Abstract Objective Abnormalities in the eutopic endometrium of women with endometriosis may be related to disease-associated infertility. Although previous RNA-sequencing analysis did not show differential expression in endometrial transcripts of endometriosis patients, other molecular alterations could impact protein synthesis and endometrial receptivity. Our aim was to screen for functional mutations in the transcripts of eutopic endometria of infertile women with endometriosis and controls during the implantation window. Methods Data from RNA-Sequencing of endometrial biopsies collected during the implantation window from 17 patients (6 infertile women with endometriosis, 6 infertile controls, 5 fertile controls) were analyzed for variant discovery and identification of functional mutations. A targeted study of the alterations found was performed to understand the data into disease's context. Results None of the variants identified was common to other samples within the same group, and no mutation was repeated among patients with endometriosis, infertile and fertile controls. In the endometriosis group, nine predicted deleterious mutations were identified, but only one was previously associated to a clinical condition with no endometrial impact. When crossing the mutated genes with the descriptors endometriosis and/or endometrium, the gene CMKLR1 was associated either with inflammatory response in endometriosis or with endometrial processes for pregnancy establishment. Conclusion Despite no pattern of mutation having been found, we ponder the small sample size and the analysis on RNA-sequencing data. Considering the purpose of the study of screening and the importance of the CMKLR1 gene on endometrial

Resumo Objetivo Anormalidades no endométrio eutópico de mulheres com endometriose podem estar relacionadas à infertilidade associada à doença. Embora a análise prévia de sequenciamento de RNA não tenha evidenciado expressão diferencial em transcritos endometriais de pacientes com endometriose, outras alterações moleculares poderiam afetar a síntese de proteínas e a receptividade endometrial. Nosso objetivo foi rastrear mutações funcionais em transcritos de endométrios eutópicos de mulheres inférteis com endometriose e de controles durante a janela de implantação. Métodos Os dados do sequenciamento de RNA de biópsias endometriais coletados durante a janela de implantação de 17 pacientes (6 mulheres inférteis com endometriose, 6 controles inférteis, 5 controles férteis) foram analisados para a descoberta de variantes e a identificação de mutações funcionais. Um estudo direcionado das alterações encontradas foi realizado para compreender os dados no contexto da doença. Resultados Nenhuma das variantes identificadas foi comuma outras amostras dentro do mesmo grupo, assim como nenhuma mutação se repetiu entre pacientes com endometriose, controles inférteis e férteis. No grupo de endometriose, foram identificadas nove mutações deletérias preditas, mas apenas uma foi previamente associada a uma condição clínica sem impacto endometrial. Ao cruzar os genes mutados com os descritores endometriose e/ou endométrio, o gene CMKLR1 foi associado a resposta inflamatória na endometriose e a processos endometriais para estabelecimento da gravidez. Conclusão Apesar de nenhum padrão de mutação ter sido encontrado, ponderamos o pequeno tamanho da amostra e a análise dos dados de sequenciamento de RNA. Considerando o objetivo do estudo de triagem e a importância do gene CMKLR1 na modulação endometrial, este poderia ser um gene candidato para estudos adicionais que avaliem mutações no endométrio eutópico de pacientes com endometriose.

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.

Application prospects of single-cell transcriptome sequencing in traditional Chinese medicine research / 中国中药杂志

Single-cell transcriptome sequencing(scRNA-seq) can be used to analyze the expression characteristics of the transcriptome at the level of individual cell, and discover the heterogeneity of gene expression in individual cell that is "diluted" or averaged in study of group organization. The scRNA-seq, with the characteristics of standardization, high-throughput, and high integration, can greatly simplify the experimental operation and significantly reduce the consumption of reagents. At the same time, a variety of cells are screened and the gene expression patterns are analyzed at the single-cell level to provide a more efficient detection technique and more rich and accurate information for drug research. In the field of traditional Chinese medicine(TCM), the scRNA-seq is still a new technology, but the individual and precision concepts embodied by scRNA-seq and the theory of TCM syndrome differentiation and treatment have reached the same effect between the micro and macro aspects. This study tried to broaden the thinking for the modernization of TCM by introducing the development of scRNA-seq technology and its application in modern drug research and discussing the application prospects of scRNA-seq in TCM research.

Single-cell analysis of angiotensin-converting enzyme II expression in human kidneys and bladders reveals a potential route of 2019 novel coronavirus infection / 中华医学杂志(英文版)

BACKGROUND@#Since 2019, a novel coronavirus named 2019 novel coronavirus (2019-nCoV) has emerged worldwide. Apart from fever and respiratory complications, acute kidney injury has been observed in a few patients with coronavirus disease 2019. Furthermore, according to recent findings, the virus has been detected in urine. Angiotensin-converting enzyme II (ACE2) has been proposed to serve as the receptor for the entry of 2019-nCoV, which is the same as that for the severe acute respiratory syndrome. This study aimed to investigate the possible cause of kidney damage and the potential route of 2019-nCoV infection in the urinary system.@*METHODS@#We used both published kidney and bladder cell atlas data and new independent kidney single-cell RNA sequencing data generated in-house to evaluate ACE2 gene expression in all cell types in healthy kidneys and bladders. The Pearson correlation coefficients between ACE2 and all other genes were first generated. Then, genes with r values larger than 0.1 and P values smaller than 0.01 were deemed significant co-expression genes with ACE2.@*RESULTS@#Our results showed the enriched expression of ACE2 in all subtypes of proximal tubule (PT) cells of the kidney. ACE2 expression was found in 5.12%, 5.80%, and 14.38% of the proximal convoluted tubule cells, PT cells, and proximal straight tubule cells, respectively, in three published kidney cell atlas datasets. In addition, ACE2 expression was also confirmed in 12.05%, 6.80%, and 10.20% of cells of the proximal convoluted tubule, PT, and proximal straight tubule, respectively, in our own two healthy kidney samples. For the analysis of public data from three bladder samples, ACE2 expression was low but detectable in bladder epithelial cells. Only 0.25% and 1.28% of intermediate cells and umbrella cells, respectively, had ACE2 expression.@*CONCLUSION@#This study has provided bioinformatics evidence of the potential route of 2019-nCoV infection in the urinary system.

Identify Myeloid Differentiation-Related MiRNAs Response to ATRA Induction by RNA Sequencing and CRISPR/Cas9 Gene Editing / 中国实验血液学杂志

OBJECTIVE@#To identify differentiation related miRNA and evaluate roles of miRNA during ATRA induced myeloid differentiation.@*METHODS@#The small RNA sequencing was used to analyze differential expressed miRNAs in ATRA induced NB4 cells. Then the several up or down-regulated miRNA were selected as the research candidates. SgRNAs targeting the genome of each miRNA were designed and NB4 cells with inducible expression of Cas9 protein were generated. After transduced sgRNA into NB4/Cas9 cells, the mutation level by PCR and surveyor assay were evaluated. The cell differentiation level was investigated by surface CD11b expression via flow cytometry.@*RESULTS@#A total of 410 mature miRNAs which expressed in NB4 cells were detected out after treated by ATRA, 74 miRNAs were up-regulated and 55 were down-regulated miRNAs with DNA cleavage generated by CRISPR/Cas9 was assayed directly by PCR or surveyor assay, quantitative PCR showed that the expression of miRNA was downregulated, which evaluated that gene edition successfully inhibitied the expression of mature miRNA. MiR-223 knockout showed the myeloid differentation of NB4 significantly inhibitied, while miRNA-155 knockout showed the myeloid differentation of NB4 cells significantly increased.@*CONCLUSION@#CRISPR/Cas9 is a powerful tool for gene editing and can lead to miRNA knockout. Knockouts of miR-223 and miR-155 have shown a differentiation-related phenotype, and the potential mechanism is the integrative regulation of target genes.

From bulk, single-cell to spatial RNA sequencing / 国际口腔科学杂志·英文版

RNA sequencing (RNAseq) can reveal gene fusions, splicing variants, mutations/indels in addition to differential gene expression, thus providing a more complete genetic picture than DNA sequencing. This most widely used technology in genomics tool box has evolved from classic bulk RNA sequencing (RNAseq), popular single cell RNA sequencing (scRNAseq) to newly emerged spatial RNA sequencing (spRNAseq). Bulk RNAseq studies average global gene expression, scRNAseq investigates single cell RNA biology up to 20,000 individual cells simultaneously, while spRNAseq has ability to dissect RNA activities spatially, representing next generation of RNA sequencing. This article highlights these technologies, characteristic features and suitable applications in precision oncology.

Functional and genomic characterization of three novel cell lines derived from a metastatic gallbladder cancer tumor

BACKGROUND: Gallbladder cancer (GBC) is the most common tumor of the biliary tract. The incidence of GBC shows a large geographic variability, being particularly frequent in Native American populations. In Chile, GBC represents the second cause of cancer-related death among women. We describe here the establishment of three novel cell lines derived from the ascitic fluid of a Chilean GBC patient, who presented 46% European, 36% Mapuche, 12% Aymara and 6% African ancestry. RESULTS: After immunocytochemical staining of the primary cell culture, we isolated and comprehensively characterized three independent clones (PUC-GBC1, PUC-GBC2 and PUC-GBC3) by short tandem repeat DNA profiling and RNA sequencing as well as karyotype, doubling time, chemosensitivity, in vitro migration capability and in vivo tumorigenicity assay. Primary culture cells showed high expression of CK7, CK19, CA 19-9, MUC1 and MUC16, and negative expression of mesothelial markers. The three isolated clones displayed an epithelial phenotype and an abnormal structure and number of chromosomes. RNA sequencing confirmed the increased expression of cytokeratin and mucin genes, and also of TP53 and ERBB2 with some differences among the three cells lines, and revealed a novel exonic mutation in NF1. The PUC-GBC3 clone was the most aggressive according to histopathological features and the tumorigenic capacity in NSG mice. CONCLUSIONS: The first cell lines established from a Chilean GBC patient represent a new model for studying GBC in patients of Native American descent.

The role of Candida albicans in root caries biofilms: an RNA-seq analysis

Abstract Objective This study sought to analyze the gene expression of Candida albicans in sound root surface and root caries lesions, exploring its role in root caries pathogenesis. Methodology The differential gene expression of C. albicans and the specific genes related to cariogenic traits were studied in association with samples of biofilm collected from exposed sound root surface (SRS, n=10) and from biofilm and carious dentin of active root carious lesions (RC, n=9). The total microbial RNA was extracted, and the cDNA libraries were prepared and sequenced on the Illumina Hi-Seq2500. Unique reads were mapped to 163 oral microbial reference genomes including two chromosomes of C. albicans SC5314 (14,217 genes). The putative presence of C. albicans was estimated (sum of reads/total number of genes≥1) in each sample. Count data were normalized (using the DESeq method package) to analyze differential gene expression (using the DESeq2R package) applying the Benjamini-Hochberg correction (FDR<0.05). Results Two genes (CaO19.610, FDR=0.009; CaO19.2506, FDR=0.018) were up-regulated on SRS, and their functions are related to biofilm formation. Seven genes ( UTP20 , FDR=0.018; ITR1 , FDR=0.036; DHN6 , FDR=0.046; CaO19.7197 , FDR=0.046; CaO19.7838 , FDR=0.046; STT4 , FDR=0.046; GUT1 , FDR=0.046) were up-regulated on RC and their functions are related to metabolic activity, sugar transport, stress tolerance, invasion and pH regulation. The use of alternative carbon sources, including lactate, and the ability to form hypha may be a unique trait of C. albicans influencing biofilm virulence. Conclusions C. albicans is metabolically active in SRS and RC biofilm, with different roles in health and disease.

Computational prediction and characterisation of miRNAs and their pathway genes in human schistosomiasis caused by Schistosoma haematobium

BACKGROUND Key genes control the infectivity of the Schistosoma haematobium causing schistosomiasis. A method for understanding the regulation of these genes might help in developing new disease strategies to control schistosomiasis, such as the silencing mediated by microRNAs (miRNAs). The miRNAs have been studied in schistosome species and they play important roles in the post-transcriptional regulation of genes, and in parasite-host interactions. However, genome-wide identification and characterisation of novel miRNAs and their pathway genes and their gene expression have not been explored deeply in the genome and transcriptome of S. haematobium. OBJECTIVES Identify and characterise mature and precursor miRNAs and their pathway genes in the S. haematobium genome. METHODS Computational prediction and characterisation of miRNAs and genes involved in miRNA pathway from S. haematobium genome on SchistoDB. Conserved domain analysis was performed using PFAM and CDD databases. A robust algorithm was applied to identify mature miRNAs and their precursors. The characterisation of the precursor miRNAs was performed using RNAfold, RNAalifold and Perl scripts. FINDINGS We identified and characterised 14 putative proteins involved in miRNA pathway including ARGONAUTE and DICER in S. haematobium. Besides that, 149 mature miRNAs and 131 precursor miRNAs were identified in the genome including novel miRNAs. MAIN CONCLUSIONS miRNA pathway occurs in the S. haematobium, including endogenous miRNAs and miRNA pathway components, suggesting a role of this type of non-coding RNAs in gene regulation in the parasite. The results found in this work will open up a new avenue for studying miRNAs in the S. haematobium biology in helping to understand the mechanism of gene silencing in the human parasite Schistosome.

A human circulating immune cell landscape in aging and COVID-19

Age-associated changes in immune cells have been linked to an increased risk for infection. However, a global and detailed characterization of the changes that human circulating immune cells undergo with age is lacking. Here, we combined scRNA-seq, mass cytometry and scATAC-seq to compare immune cell types in peripheral blood collected from young and old subjects and patients with COVID-19. We found that the immune cell landscape was reprogrammed with age and was characterized by T cell polarization from naive and memory cells to effector, cytotoxic, exhausted and regulatory cells, along with increased late natural killer cells, age-associated B cells, inflammatory monocytes and age-associated dendritic cells. In addition, the expression of genes, which were implicated in coronavirus susceptibility, was upregulated in a cell subtype-specific manner with age. Notably, COVID-19 promoted age-induced immune cell polarization and gene expression related to inflammation and cellular senescence. Therefore, these findings suggest that a dysregulated immune system and increased gene expression associated with SARS-CoV-2 susceptibility may at least partially account for COVID-19 vulnerability in the elderly.

A human circulating immune cell landscape in aging and COVID-19

Age-associated changes in immune cells have been linked to an increased risk for infection. However, a global and detailed characterization of the changes that human circulating immune cells undergo with age is lacking. Here, we combined scRNA-seq, mass cytometry and scATAC-seq to compare immune cell types in peripheral blood collected from young and old subjects and patients with COVID-19. We found that the immune cell landscape was reprogrammed with age and was characterized by T cell polarization from naive and memory cells to effector, cytotoxic, exhausted and regulatory cells, along with increased late natural killer cells, age-associated B cells, inflammatory monocytes and age-associated dendritic cells. In addition, the expression of genes, which were implicated in coronavirus susceptibility, was upregulated in a cell subtype-specific manner with age. Notably, COVID-19 promoted age-induced immune cell polarization and gene expression related to inflammation and cellular senescence. Therefore, these findings suggest that a dysregulated immune system and increased gene expression associated with SARS-CoV-2 susceptibility may at least partially account for COVID-19 vulnerability in the elderly.

Review of a novel disease entity, immunoglobulin G4-related disease

Immunoglobulin G4 (IgG4)-related dacryoadenitis and sialoadenitis (IgG4-DS) are part of a multiorgan fibroinflammatory condition of unknown etiology termed IgG4-related disease (IgG4-RD), which has been recognized as a single diagnostic entity for less than 15 years. Histopathologic examination is critical for diagnosis of IgG4-RD. CD4+ T and B cells, including IgG4-expressing plasma cells, constitute the major inflammatory cell populations in IgG4-RD and are thought to cause organ damage and tissue fibrosis. Patients with IgG4-RD who have active, untreated disease exhibit significant increase of IgG4-secreting plasmablasts in the blood. Considerable insight into the immunologic mechanisms of IgG4-RD has been achieved in the last decade using novel molecular biology approaches, including next-generation and single-cell RNA sequencing. Exploring the interactions between CD4+ T cells and B lineage cells is critical for understanding the pathophysiology of IgG4-RD. Establishment of pathogenic T cell clones and identification of antigens specific to these clones constitutes the first steps in determining the pathogenesis of the disease. Herein, the clinical features and mechanistic insights regarding pathogenesis of IgG4-RD were reviewed.

Understanding the Molecular Mechanisms of Asthma through Transcriptomics

The transcriptome represents the complete set of RNA transcripts that are produced by the genome under a specific circumstance or in a specific cell. High-throughput methods, including microarray and bulk RNA sequencing, as well as recent advances in biostatistics based on machine learning approaches provides a quick and effective way of identifying novel genes and pathways related to asthma, which is a heterogeneous disease with diverse pathophysiological mechanisms. In this manuscript, we briefly review how to analyze transcriptome data and then provide a summary of recent transcriptome studies focusing on asthma pathogenesis and asthma drug responses. Studies reviewed here are classified into 2 classes based on the tissues utilized: blood and airway cells.

Identification of key enzyme genes involved in biosynthesis of steroidal saponins and analysis of biosynthesis pathway in Polygonatum cyrtonema / 中国中药杂志

Steroidal saponins, which are the characteristic and main active constituents of Polygonatum, exhibit a broad range of pharmacological functions, such as regulating blood sugar, preventing cardiovascular and cerebrovascular diseases and anti-tumor. In this study, we performed RNA sequencing(RNA-Seq) analysis for the flowers, leaves, roots, and rhizomes of Polygonatum cyrtonema using the BGISEQ-500 platform to understand the biosynthesis pathway of steroidal saponins and study their key enzyme genes. The assembly of transcripts for four tissues generated 129 989 unigenes, of which 88 958 were mapped to several public databases for functional annotation, 22 813 unigenes were assigned to 53 subcategories and 64 877 unigenes were annotated to 136 pathways in KEGG database. Furthermore, 502 unigenes involved in the biosynthesis pathway of steroidal saponins were identified, of which 97 unigenes encoding 12 key enzymes. Cycloartenol synthase, the first key enzyme in the pathway of phytosterol biosynthesis, showed conserved catalytic domain and substrate binding domain based on sequence analysis and homology modeling. Differentially expressed genes(DEGs) were identified in rhizomes as compared to other tissues(flowers, leaves or roots).The 2 437 unigenes annotated by KEGG showed rhizome-specific expression, of which 35 unigenes involved in the biosynthesis of steroidal saponins. Our results greatly extend the public transcriptome dataset of Polygonatum and provide valuable information for the identification of candidate genes involved in the biosynthesis of steroidal saponins and other important secondary metabolites.