RESUMO
Rationale: Bronchiectasis is a pathological dilatation of the bronchi in the respiratory airways associated with environmental or genetic causes (e.g., cystic fibrosis, primary ciliary dyskinesia, and primary immunodeficiency disorders), but most cases remain idiopathic. Objectives: To identify novel genetic defects in unsolved cases of bronchiectasis presenting with severe rhinosinusitis, nasal polyposis, and pulmonary Pseudomonas aeruginosa infection. Methods: DNA was analyzed by next-generation or targeted Sanger sequencing. RNA was analyzed by quantitative PCR and single-cell RNA sequencing. Patient-derived cells, cell cultures, and secretions (mucus, saliva, seminal fluid) were analyzed by Western blotting and immunofluorescence microscopy, and mucociliary activity was measured. Blood serum was analyzed by electrochemiluminescence immunoassay. Protein structure and proteomic analyses were used to assess the impact of a disease-causing founder variant. Measurements and Main Results: We identified biallelic pathogenic variants in WAP four-disulfide core domain 2 (WFDC2) in 11 individuals from 10 unrelated families originating from the United States, Europe, Asia, and Africa. Expression of WFDC2 was detected predominantly in secretory cells of control airway epithelium and also in submucosal glands. We demonstrate that WFDC2 is below the limit of detection in blood serum and hardly detectable in samples of saliva, seminal fluid, and airway surface liquid from WFDC2-deficient individuals. Computer simulations and deglycosylation assays indicate that the disease-causing founder variant p.Cys49Arg structurally hampers glycosylation and, thus, secretion of mature WFDC2. Conclusions: WFDC2 dysfunction defines a novel molecular etiology of bronchiectasis characterized by the deficiency of a secreted component of the airways. A commercially available blood test combined with genetic testing allows its diagnosis.
Assuntos
Bronquiectasia , Pólipos Nasais , Adolescente , Adulto , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Bronquiectasia/genética , Bronquiectasia/fisiopatologia , Pólipos Nasais/genética , Proteína 2 do Domínio Central WAP de Quatro DissulfetosRESUMO
The human airway mucociliary epithelium can be recapitulated in vitro using primary cells cultured in an air-liquid interface (ALI), a reliable surrogate to perform pathophysiological studies. As tremendous variations exist among media used for ALI-cultured human airway epithelial cells, the aim of our study was to evaluate the impact of several media (BEGM, PneumaCult, Half & Half, and Clancy) on cell type distribution using single-cell RNA sequencing and imaging. Our work revealed the impact of these media on cell composition, gene expression profile, cell signaling, and epithelial morphology. We found higher proportions of multiciliated cells in PneumaCult-ALI and Half & Half, stronger EGF signaling from basal cells in BEGM-ALI, differential expression of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) entry factor ACE2, and distinct secretome transcripts depending on the media used. We also established that proliferation in PneumaCult-Ex Plus favored secretory cell fate, showing the key influence of proliferation media on late differentiation epithelial characteristics. Altogether, our data offer a comprehensive repertoire for evaluating the effects of culture conditions on airway epithelial differentiation and will aid in choosing the most relevant medium according to the processes to be investigated, such as cilia, mucus biology, or viral infection. We detail useful parameters that should be explored to document airway epithelial cell fate and morphology.
Assuntos
Diferenciação Celular , Proliferação de Células , Células Epiteliais , Mucosa Respiratória , Humanos , Mucosa Respiratória/citologia , Mucosa Respiratória/metabolismo , Células Epiteliais/metabolismo , Células Epiteliais/citologia , Regeneração , Células Cultivadas , SARS-CoV-2 , COVID-19/virologia , COVID-19/patologia , COVID-19/metabolismo , Técnicas de Cultura de Células/métodos , Enzima de Conversão de Angiotensina 2/metabolismo , Enzima de Conversão de Angiotensina 2/genética , Meios de CulturaRESUMO
A finely regulated system of airway epithelial development governs the differentiation of motile ciliated cells of the human respiratory tract, conferring the body's mucociliary clearance defence system. Human cilia dysfunction can arise through genetic mutations and this is a cause of debilitating disease morbidities that confer a greatly reduced quality of life. The inherited human motile ciliopathy disorder, primary ciliary dyskinesia (PCD), can arise from mutations in genes affecting various aspects of motile cilia structure and function through deficient production, transport and assembly of cilia motility components or through defective multiciliogenesis. Our understanding about the development of the respiratory epithelium, motile cilia biology and the implications for human pathology has expanded greatly over the past 20 years since isolation of the first PCD gene, rising to now nearly 50 genes. Systems level insights about cilia motility in health and disease have been made possible through intensive molecular and omics (genomics, transcriptomics, proteomics) research, applied in ciliate organisms and in animal and human disease modelling. Here, we review ciliated airway development and the genetic stratification that underlies PCD, for which the underlying genotype can increasingly be connected to biological mechanism and disease prognostics. Progress in this field can facilitate clinical translation of research advances, with potential for great medical impact, e.g. through improvements in ciliopathy disease diagnosis, management, family counselling and by enhancing the potential for future genetically tailored approaches to disease therapeutics.
Assuntos
Dineínas do Axonema/genética , Cílios/metabolismo , Transtornos da Motilidade Ciliar/genética , Proteínas do Olho/genética , Mutação , Mucosa Respiratória/metabolismo , Animais , Dineínas do Axonema/metabolismo , Cílios/patologia , Cílios/ultraestrutura , Transtornos da Motilidade Ciliar/metabolismo , Transtornos da Motilidade Ciliar/patologia , Proteínas do Olho/metabolismo , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Regulação da Expressão Gênica , Genótipo , Humanos , Padrões de Herança , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas/genética , Proteínas/metabolismo , Qualidade de Vida , Mucosa Respiratória/patologia , Mucosa Respiratória/ultraestrutura , Transdução de SinaisRESUMO
The upper airway epithelium, which is mainly composed of multiciliated, goblet, club and basal cells, ensures proper mucociliary function and can regenerate in response to assaults. In chronic airway diseases, defective repair leads to tissue remodeling. Delineating key drivers of differentiation dynamics can help understand how normal or pathological regeneration occurs. Using single-cell transcriptomics and lineage inference, we have unraveled trajectories from basal to luminal cells, providing novel markers for specific populations. We report that: (1) a precursor subgroup of multiciliated cells, which we have entitled deuterosomal cells, is defined by specific markers, such as DEUP1, FOXN4, YPEL1, HES6 and CDC20B; (2) goblet cells can be precursors of multiciliated cells, thus explaining the presence of hybrid cells that co-express markers of goblet and multiciliated cells; and (3) a repertoire of molecules involved in the regeneration process, such as keratins or components of the Notch, Wnt or BMP/TGFß pathways, can be identified. Confirmation of our results on fresh human and pig airway samples, and on mouse tracheal cells, extend and confirm our conclusions regarding the molecular and cellular choreography at work during mucociliary epithelial differentiation.
Assuntos
Diferenciação Celular/fisiologia , Células Epiteliais/citologia , Células Caliciformes/citologia , Mucosa Respiratória/citologia , Animais , Diferenciação Celular/genética , Células Cultivadas , Células Epiteliais/metabolismo , Células Caliciformes/metabolismo , Humanos , Camundongos , RNA-Seq , Mucosa Respiratória/metabolismo , Suínos , Traqueia/citologia , Traqueia/metabolismoRESUMO
The Human Cell Atlas (HCA) consortium aims to establish an atlas of all organs in the healthy human body at single-cell resolution to increase our understanding of basic biological processes that govern development, physiology and anatomy, and to accelerate diagnosis and treatment of disease. The Lung Biological Network of the HCA aims to generate the Human Lung Cell Atlas as a reference for the cellular repertoire, molecular cell states and phenotypes, and cell-cell interactions that characterise normal lung homeostasis in healthy lung tissue. Such a reference atlas of the healthy human lung will facilitate mapping the changes in the cellular landscape in disease. The discovAIR project is one of six pilot actions for the HCA funded by the European Commission in the context of the H2020 framework programme. discovAIR aims to establish the first draft of an integrated Human Lung Cell Atlas, combining single-cell transcriptional and epigenetic profiling with spatially resolving techniques on matched tissue samples, as well as including a number of chronic and infectious diseases of the lung. The integrated Human Lung Cell Atlas will be available as a resource for the wider respiratory community, including basic and translational scientists, clinical medicine, and the private sector, as well as for patients with lung disease and the interested lay public. We anticipate that the Human Lung Cell Atlas will be the founding stone for a more detailed understanding of the pathogenesis of lung diseases, guiding the design of novel diagnostics and preventive or curative interventions.
Assuntos
Pneumopatias , Pulmão , Humanos , Proteômica , TóraxRESUMO
Mammary carcinoma, including triple-negative breast carcinomas (TNBC) are tumor-types for which human and canine pathologies are closely related at the molecular level. The efficacy of an oncolytic vaccinia virus (VV) was compared in low-passage primary carcinoma cells from TNBC versus non-TNBC. Non-TNBC cells were 28 fold more sensitive to VV than TNBC cells in which VV replication is impaired. Single-cell RNA-seq performed on two different TNBC cell samples, infected or not with VV, highlighted three distinct populations: naïve cells, bystander cells, defined as cells exposed to the virus but not infected and infected cells. The transcriptomes of these three populations showed striking variations in the modulation of pathways regulated by cytokines and growth factors. We hypothesized that the pool of genes expressed in the bystander populations was enriched in antiviral genes. Bioinformatic analysis suggested that the reduced activity of the virus was associated with a higher mesenchymal status of the cells. In addition, we demonstrated experimentally that high expression of one gene, DDIT4, is detrimental to VV production. Considering that DDIT4 is associated with a poor prognosis in various cancers including TNBC, our data highlight DDIT4 as a candidate resistance marker for oncolytic poxvirus therapy. This information could be used to design new generations of oncolytic poxviruses. Beyond the field of gene therapy, this study demonstrates that single-cell transcriptomics can be used to identify cellular factors influencing viral replication.
Assuntos
Neoplasias Mamárias Animais/metabolismo , Terapia Viral Oncolítica/métodos , Fatores de Transcrição/metabolismo , Transcriptoma , Vaccinia virus/genética , Vacínia/metabolismo , Replicação Viral , Animais , Biologia Computacional , Cães , Feminino , Neoplasias Mamárias Animais/genética , Neoplasias Mamárias Animais/terapia , Neoplasias Mamárias Animais/virologia , Análise de Célula Única , Fatores de Transcrição/genética , Vacínia/genética , Vacínia/virologiaRESUMO
Rationale: The respiratory tract constitutes an elaborate line of defense that is based on a unique cellular ecosystem.Objectives: We aimed to investigate cell population distributions and transcriptional changes along the airways by using single-cell RNA profiling.Methods: We have explored the cellular heterogeneity of the human airway epithelium in 10 healthy living volunteers by single-cell RNA profiling. A total of 77,969 cells were collected at 35 distinct locations, from the nose to the 12th division of the airway tree.Measurements and Main Results: The resulting atlas is composed of a high percentage of epithelial cells (89.1%) but also immune (6.2%) and stromal (4.7%) cells with distinct cellular proportions in different regions of the airways. It reveals differential gene expression between identical cell types (suprabasal, secretory, and multiciliated cells) from the nose (MUC4, PI3, SIX3) and tracheobronchial (SCGB1A1, TFF3) airways. By contrast, cell-type-specific gene expression is stable across all tracheobronchial samples. Our atlas improves the description of ionocytes, pulmonary neuroendocrine cells, and brush cells and identifies a related population of NREP-positive cells. We also report the association of KRT13 with dividing cells that are reminiscent of previously described mouse "hillock" cells and with squamous cells expressing SCEL and SPRR1A/B.Conclusions: Robust characterization of a single-cell cohort in healthy airways establishes a valuable resource for future investigations. The precise description of the continuum existing from the nasal epithelium to successive divisions of the airways and the stable gene expression profile of these regions better defines conditions under which relevant tracheobronchial proxies of human respiratory diseases can be developed.
Assuntos
Brônquios/citologia , Brônquios/crescimento & desenvolvimento , Diferenciação Celular/genética , Proliferação de Células/genética , Células Epiteliais/citologia , Mucosa Nasal/citologia , Mucosa Nasal/crescimento & desenvolvimento , Células Estromais/citologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Regulação da Expressão Gênica , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Experimental evidence indicates that about 60% of miRNA-binding activity does not follow the canonical rule about the seed matching between miRNA and target mRNAs, but rather a non-canonical miRNA targeting activity outside the seed or with a seed-like motifs. Here, we propose a new unbiased method to identify canonical and non-canonical miRNA-binding sites from peaks identified by Ago2 Cross-Linked ImmunoPrecipitation associated to high-throughput sequencing (CLIP-seq). Since the quality of peaks is of pivotal importance for the final output of the proposed method, we provide a comprehensive benchmarking of four peak detection programs, namely CIMS, PIPE-CLIP, Piranha and Pyicoclip, on four publicly available Ago2-HITS-CLIP datasets and one unpublished in-house Ago2-dataset in stem cells. We measured the sensitivity, the specificity and the position accuracy toward miRNA binding sites identification, and the agreement with TargetScan. Secondly, we developed a new pipeline, called miRBShunter, to identify canonical and non-canonical miRNA-binding sites based on de novo motif identification from Ago2 peaks and prediction of miRNA::RNA heteroduplexes. miRBShunter was tested and experimentally validated on the in-house Ago2-dataset and on an Ago2-PAR-CLIP dataset in human stem cells. Overall, we provide guidelines to choose a suitable peak detection program and a new method for miRNA-target identification.
Assuntos
Sequenciamento de Nucleotídeos em Larga Escala , MicroRNAs/metabolismo , Motivos de Aminoácidos , Proteínas Argonautas/química , Proteínas Argonautas/genética , Benchmarking , Sítios de Ligação , Humanos , MicroRNAs/química , Conformação de Ácido Nucleico , Sensibilidade e Especificidade , SoftwareRESUMO
Single cell RNA sequencing approaches are instrumental in studies of cell-to-cell variability. 5Î selective transcriptome profiling approaches allow simultaneous definition of the transcription start size and have advantages over 3Î selective approaches which just provide internal sequences close to the 3Î end. The only currently existing 5Î selective approach requires costly and labor intensive fragmentation and cell barcoding after cDNA amplification. We developed an optimized 5Î selective workflow where all the cell indexing is done prior to fragmentation. With our protocol, cell indexing can be performed in the Fluidigm C1 microfluidic device, resulting in a significant reduction of cost and labor. We also designed optimized unique molecular identifiers that show less sequence bias and vulnerability towards sequencing errors resulting in an improved accuracy of molecule counting. We provide comprehensive experimental workflows for Illumina and Ion Proton sequencers that allow single cell sequencing in a cost range comparable to qPCR assays.
Assuntos
Perfilação da Expressão Gênica/métodos , Análise de Sequência de RNA/métodos , Células Cultivadas , DNA Complementar , Perfilação da Expressão Gênica/economia , Células HEK293 , Humanos , Análise de Sequência de RNA/economia , Análise de Célula ÚnicaRESUMO
Despite the importance of mucociliary epithelia in animal physiology, the mechanisms controlling their establishment are poorly understood. Using the developing Xenopus epidermis and regenerating human upper airways, we reveal the importance of BMP signalling for the construction of vertebrate mucociliary epithelia. In Xenopus, attenuation of BMP activity is necessary for the specification of multiciliated cells (MCCs), ionocytes and small secretory cells (SSCs). Conversely, BMP activity is required for the proper differentiation of goblet cells. Our data suggest that the BMP and Notch pathways interact to control fate choices in the developing epidermis. Unexpectedly, BMP activity is also necessary for the insertion of MCCs, ionocytes and SSCs into the surface epithelium. In human, BMP inhibition also strongly stimulates the formation of MCCs in normal and pathological (cystic fibrosis) airway samples, whereas BMP overactivation has the opposite effect. This work identifies the BMP pathway as a key regulator of vertebrate mucociliary epithelium differentiation and morphogenesis.
Assuntos
Proteínas Morfogenéticas Ósseas/metabolismo , Cílios/metabolismo , Epitélio/embriologia , Epitélio/metabolismo , Transdução de Sinais , Vertebrados/embriologia , Vertebrados/metabolismo , Animais , Padronização Corporal , Linhagem da Célula , Células Cultivadas , Células Epidérmicas , Epiderme/embriologia , Células Epiteliais/metabolismo , Feminino , Humanos , Pulmão/citologia , Regeneração , Xenopus , Proteínas de Xenopus/metabolismoRESUMO
Syndecan-1 (SDC1/CD138) is one of the main cell surface proteoglycans and is involved in crucial biological processes. Only a few studies have analyzed the role of SDC1 in mesenchymal tumor pathogenesis. In particular, its involvement in adipose tissue tumors has never been investigated. Dedifferentiated liposarcoma, one of the most frequent types of malignant adipose tumors, has a high potential of recurrence and metastastic evolution. Classical chemotherapy is inefficient in metastatic dedifferentiated liposarcoma and novel biological markers are needed for improving its treatment. In this study, we have analyzed the expression of SDC1 in well-differentiated/dedifferentiated liposarcomas and showed that SDC1 is highly overexpressed in dedifferentiated liposarcoma compared with normal adipose tissue and lipomas. Silencing of SDC1 in liposarcoma cells impaired cell viability and proliferation. Using the human multipotent adipose-derived stem cell model of human adipogenesis, we showed that SDC1 promotes proliferation of undifferentiated adipocyte progenitors and inhibits their adipogenic differentiation. Altogether, our results support the hypothesis that SDC1 might be involved in liposarcomagenesis. It might play a prominent role in the dedifferentiation process occurring when well-differentiated liposarcoma progress to dedifferentiated liposarcoma. Targeting SDC1 in these tumors might provide a novel therapeutic strategy.
Assuntos
Adipogenia , Tecido Adiposo/patologia , Diferenciação Celular , Transformação Celular Neoplásica/patologia , Lipossarcoma/patologia , Sindecana-1/metabolismo , Tecido Adiposo/metabolismo , Western Blotting , Proliferação de Células , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Células Cultivadas , Citometria de Fluxo , Humanos , Técnicas Imunoenzimáticas , Lipossarcoma/genética , Lipossarcoma/metabolismo , RNA Mensageiro/genética , RNA Interferente Pequeno/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células-Tronco/metabolismo , Células-Tronco/patologia , Sindecana-1/antagonistas & inibidores , Sindecana-1/genéticaRESUMO
BACKGROUND: Data from next generation sequencing technologies uncovered the existence of many classes of small RNAs. Recent studies reported that small RNAs are released by cells and can be detected in the blood. In this report, we aimed to discover the occurrence of novel circulating small RNAs in coronary artery disease (CAD). METHODS: We used high-throughput sequencing of small RNAs from human and mouse apoptotic primary macrophages, and analyzed the data by empirical Bayes moderated t-statistics to assess differential expression and the Benjamini and Hochberg method to control the false discovery rate. Results were then confirmed by Northern blot and RT-qPCR in foam cells and in two animal models for atherosclerosis, namely ApoE(-/-) and Ldlr(-/-) mouse lines. Quantitative RT-PCR to detect identified small RNAs, the RNY-derived small RNAs, was performed using sera of 263 patients with CAD compared to 514 matched healthy controls; the Student t-test was applied to statistically assess differences. Associations of small RNAs with clinical characteristics and biological markers were tested using Spearman's rank correlations, while multivariate logistic regressions were performed to test the statistical association of small RNA levels with CAD. RESULTS: Here, we report that, in macrophages stimulated with pro-apoptotic or pro-atherogenic stimuli, the Ro-associated non-coding RNAs, called RNYs or Y-RNAs, are processed into small RNAs (~24-34 nt) referred to as small-RNYs (s-RNYs), including s-RNY1-5p processed from RNY1. A significant upregulation of s-RNY expression was found in aortic arches and blood plasma from ApoE(-/-) and Ldlr(-/-) mice and in serum from CAD patients (P <0.001). Biostatistical analysis revealed a positive association of s-RNY1-5p with hs-CRP and ApoB levels; however, no statistical interaction was found between either of these two markers and s-RNY1-5p in relation to the CAD status. Levels of s-RNY1-5p were also independent from statin and fibrate therapies. CONCLUSION: Our results position the s-RNY1-5p as a relevant novel independent diagnostic biomarker for atherosclerosis-related diseases. Measurement of circulating s-RNY expression would be a valuable companion diagnostic to monitor foam cell apoptosis during atherosclerosis pathogenesis and to evaluate patient's responsiveness to future therapeutic strategies aiming to attenuate apoptosis in foam cells in advanced atherosclerotic lesions.
Assuntos
Doença da Artéria Coronariana/sangue , RNA não Traduzido/sangue , Idoso , Animais , Aorta Torácica/metabolismo , Aterosclerose/sangue , Biomarcadores/sangue , Estudos de Casos e Controles , Linhagem Celular , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Camundongos , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pessoa de Meia-Idade , Análise de Sequência de RNARESUMO
The MIR449 genomic locus encompasses several regulators of multiciliated cell (MCC) formation (multiciliogenesis). The miR-449 homologs miR-34b/c represent additional regulators of multiciliogenesis that are transcribed from another locus. Here, we characterized the expression of BTG4, LAYN, and HOATZ, located in the MIR34B/C locus using single-cell RNA-seq and super-resolution microscopy from human, mouse, or pig multiciliogenesis models. BTG4, LAYN, and HOATZ transcripts were expressed in both precursors and mature MCCs. The Layilin/LAYN protein was absent from primary cilia, but it was expressed in apical membrane regions or throughout motile cilia. LAYN silencing altered apical actin cap formation and multiciliogenesis. HOATZ protein was detected in primary cilia or throughout motile cilia. Altogether, our data suggest that the MIR34B/C locus may gather potential actors of multiciliogenesis.
Assuntos
Cílios , MicroRNAs , Humanos , Camundongos , Animais , Suínos , Cílios/genética , Cílios/metabolismo , Actinas/metabolismo , Genoma , Genômica , MicroRNAs/genética , MicroRNAs/metabolismo , Lectinas Tipo C/metabolismoRESUMO
Single-cell technologies have transformed our understanding of human tissues. Yet, studies typically capture only a limited number of donors and disagree on cell type definitions. Integrating many single-cell datasets can address these limitations of individual studies and capture the variability present in the population. Here we present the integrated Human Lung Cell Atlas (HLCA), combining 49 datasets of the human respiratory system into a single atlas spanning over 2.4 million cells from 486 individuals. The HLCA presents a consensus cell type re-annotation with matching marker genes, including annotations of rare and previously undescribed cell types. Leveraging the number and diversity of individuals in the HLCA, we identify gene modules that are associated with demographic covariates such as age, sex and body mass index, as well as gene modules changing expression along the proximal-to-distal axis of the bronchial tree. Mapping new data to the HLCA enables rapid data annotation and interpretation. Using the HLCA as a reference for the study of disease, we identify shared cell states across multiple lung diseases, including SPP1+ profibrotic monocyte-derived macrophages in COVID-19, pulmonary fibrosis and lung carcinoma. Overall, the HLCA serves as an example for the development and use of large-scale, cross-dataset organ atlases within the Human Cell Atlas.
Assuntos
COVID-19 , Neoplasias Pulmonares , Fibrose Pulmonar , Humanos , Pulmão , Neoplasias Pulmonares/genética , MacrófagosRESUMO
The emergence and quick spread of SARS-CoV-2 has pointed at a low capacity response for testing large populations in many countries, in line of material, technical and staff limitations. The traditional RT-qPCR diagnostic test remains the reference method and is by far the most widely used test. These assays are limited to a few probe sets, require large sample PCR reaction volumes, along with an expensive and time-consuming RNA extraction step. Here we describe a quantitative nanofluidic assay that overcomes some of these shortcomings, based on the BiomarkTM instrument from Fluidigm. This system offers the possibility of performing 4608 qPCR end-points in a single run, equivalent to 192 clinical samples combined with 12 pairs of primers/probe sets in duplicate, thus allowing the monitoring of SARS-CoV-2 including the detection of specific SARS-CoV-2 variants, as well as the detection other pathogens and/or host cellular responses (virus receptors, response markers, microRNAs). The 10 nL-range volume of BiomarkTM reactions is compatible with sensitive and reproducible reactions that can be easily and cost-effectively adapted to various RT-qPCR configurations and sets of primers/probe. Finally, we also evaluated the use of inactivating lysis buffers composed of various detergents in the presence or absence of proteinase K to assess the compatibility of these buffers with a direct reverse transcription enzymatic step and we propose several protocols, bypassing the need for RNA purification. We advocate that the combined utilization of an optimized processing buffer and a high-throughput real-time PCR device would contribute to improve the turn-around-time to deliver the test results to patients and increase the SARS-CoV-2 testing capacities.
Assuntos
COVID-19/diagnóstico , Técnicas Analíticas Microfluídicas/métodos , SARS-CoV-2/isolamento & purificação , Manejo de Espécimes/métodos , Adulto , COVID-19/virologia , Teste para COVID-19/métodos , Primers do DNA , Testes Diagnósticos de Rotina/métodos , Feminino , Humanos , Masculino , MicroRNAs/genética , RNA Viral/genética , Reação em Cadeia da Polimerase em Tempo Real/métodos , SARS-CoV-2/genética , Sensibilidade e EspecificidadeRESUMO
Osteoporosis constitutes a major worldwide public health burden characterized by enhanced skeletal fragility. Bone metabolism is the combination of bone resorption by osteoclasts and bone formation by osteoblasts. Whereas increase in bone resorption is considered as the main contributor of bone loss that may lead to osteoporosis, this loss is accompanied by increased bone marrow adiposity. Osteoblasts and adipocytes share the same precursor cell and an inverse relationship exists between the two lineages. Therefore, identifying signaling pathways that stimulate mesenchymal stem cells osteogenesis at the expense of adipogenesis is of major importance for developing new therapeutic treatments. For this purpose, we identified by transcriptomic analysis the oxytocin receptor pathway as a potential regulator of the osteoblast/adipocyte balance of human multipotent adipose-derived stem (hMADS) cells. Both oxytocin (OT) and carbetocin (a stable OT analogue) negatively modulate adipogenesis while promoting osteogenesis in both hMADS cells and human bone marrow mesenchymal stromal cells. Consistent with these observations, ovariectomized (OVX) mice and rats, which become osteoporotic and exhibit disequilibrium of this balance, have significant decreased OT levels compared to sham-operated controls. Subcutaneous OT injection reverses bone loss in OVX mice and reduces marrow adiposity. Clinically, plasma OT levels are significantly lower in postmenopausal women developing osteoporosis than in their healthy counterparts. Taken together, these results suggest that plasma OT levels represent a novel diagnostic marker for osteoporosis and that OT administration holds promise as a potential therapy for this disease.
Assuntos
Células-Tronco Mesenquimais/patologia , Osteoporose/patologia , Ocitocina/fisiologia , Adipogenia , Idoso , Idoso de 80 Anos ou mais , Animais , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/metabolismo , Células da Medula Óssea/patologia , Células Cultivadas , Pré-Escolar , Feminino , Humanos , Masculino , Células-Tronco Mesenquimais/efeitos dos fármacos , Camundongos , Pessoa de Meia-Idade , Osteoblastos/metabolismo , Osteoblastos/patologia , Osteoclastos/efeitos dos fármacos , Osteoclastos/metabolismo , Osteoclastos/patologia , Osteogênese , Osteoporose/metabolismo , Osteoporose/terapia , Osteoporose Pós-Menopausa/sangue , Ovariectomia , Ocitocina/análogos & derivados , Ocitocina/sangue , Ocitocina/farmacologia , Ratos , Receptores de Ocitocina/metabolismoRESUMO
BACKGROUND: A reciprocal relationship between bone and fat development in osteoporosis is clinically well established. Some of the key molecular regulators involved in this tissue replacement process have been identified. The detailed mechanisms governing the differentiation of mesenchymal stem cells (MSC) - the key cells involved - are however only now beginning to emerge. In an attempt to address the regulation of the adipocyte/osteoblast balance at the level of gene transcription in a comprehensive and unbiased manner, we performed a large-scale gene expression profiling study using a unique cellular model, human multipotent adipose tissue-derived stem cells (hMADS). RESULTS: The analysis of 1606 genes that were found to be differentially expressed between adipogenesis and osteoblastogenesis revealed gene repression to be most prevalent prior to commitment in both lineages. Computational analyses suggested that this gene repression is mediated by miRNAs. The transcriptional activation of lineage-specific molecular processes in both cases occurred predominantly after commitment. Analyses of the gene expression data and promoter sequences produced a set of 65 genes that are candidates for genes involved in the process of adipocyte/osteoblast commitment. Four of these genes were studied in more detail: LXRalpha and phospholipid transfer protein (PLTP) for adipogenesis, the nuclear receptor COUP-TF1 and one uncharacterized gene, TMEM135 for osteoblastogenesis. PLTP was secreted during both early and late time points of hMADS adipocyte differentiation. LXRalpha, COUP-TF1, and the transmembrane protein TMEM135 were studied in primary cultures of differentiating bone marrow stromal cells from healthy donors and were found to be transcriptionally activated in the corresponding lineages. CONCLUSION: Our results reveal gene repression as a predominant early mechanism before final cell commitment. We were moreover able to identify 65 genes as candidates for genes controlling the adipocyte/osteoblast balance and to further evaluate four of these. Additional studies will explore the precise role of these candidate genes in regulating the adipogenesis/osteoblastogenesis switch.
Assuntos
Adipogenia/genética , Perfilação da Expressão Gênica , Células-Tronco Multipotentes/metabolismo , Osteoblastos/metabolismo , Regiões 3' não Traduzidas/genética , Linhagem Celular , Linhagem da Célula , Biologia Computacional , Regulação para Baixo , Regulação da Expressão Gênica no Desenvolvimento , Humanos , MicroRNAs/metabolismo , Modelos Genéticos , Análise de Sequência com Séries de Oligonucleotídeos , Regiões Promotoras Genéticas , RNA/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de TempoRESUMO
BACKGROUND: Multipotent stem cells exist within adipose tissue throughout life. An abnormal recruitment of these adipose precursor cells could participate to hyperplasia of adipose tissue observed in severe obesity or to hypoplasia of adipose tissue observed in lipodystrophy. Therefore, pharmacological molecules that control the pool of stem cells in adipose tissue are of great interest. Glycogen Synthase Kinase (GSK) 3 has been previously described as involved in differentiation of preadipose cells and might be a potential therapeutic target to modulate proliferation and differentiation of adipocyte precursors. However, the impact of GSK3 inhibition on human adipose-derived stem cells remained to be investigated. The aim of this study was to investigate GSK3 as a possible target for pharmacological inhibition of stem cell adipogenesis. To reach this goal, we studied the effects of pharmacological inhibitors of GSK3, i.e. lithium chloride (LiCl) and BIO on proliferation and adipocyte differentiation of multipotent stem cells derived from human adipose tissue. RESULTS: Our results showed that GSK3 inhibitors inhibited proliferation and clonogenicity of human stem cells, strongly suggesting that GSK3 inhibitors could be potent regulators of the pool of adipocyte precursors in adipose tissue. The impact of GSK3 inhibition on differentiation of hMADS cells was also investigated. Adipogenic and osteogenic differentiations were inhibited upon hMADS treatment with BIO. Whereas a chronic treatment was required to inhibit osteogenesis, a treatment that was strictly restricted to the early step of differentiation was sufficient to inhibit adipogenesis. CONCLUSION: These results demonstrated the feasibility of a pharmacological approach to regulate adipose-derived stem cell function and that GSK3 could represent a potential target for controlling adipocyte precursor pool under conditions where fat tissue formation is impaired.
Assuntos
Adipócitos/citologia , Tecido Adiposo/citologia , Quinase 3 da Glicogênio Sintase/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Células-Tronco/citologia , Adipócitos/efeitos dos fármacos , Adipócitos/metabolismo , Adipogenia/efeitos dos fármacos , Adipogenia/fisiologia , Tecido Adiposo/efeitos dos fármacos , Tecido Adiposo/metabolismo , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Pré-Escolar , Quinase 3 da Glicogênio Sintase/metabolismo , Humanos , Imuno-Histoquímica , Lactente , Cloreto de Lítio/farmacologia , Masculino , Células-Tronco/efeitos dos fármacos , Células-Tronco/metabolismoRESUMO
Multiciliated cells (MCCs) harbor dozens to hundreds of motile cilia, which generate hydrodynamic forces important in animal physiology. In vertebrates, MCC differentiation involves massive centriole production by poorly characterized structures called deuterosomes. Here, single-cell RNA sequencing reveals that human deuterosome stage MCCs are characterized by the expression of many cell cycle-related genes. We further investigated the uncharacterized vertebrate-specific cell division cycle 20B (CDC20B) gene, which hosts microRNA-449abc. We show that CDC20B protein associates to deuterosomes and is required for centriole release and subsequent cilia production in mouse and Xenopus MCCs. CDC20B interacts with PLK1, a kinase known to coordinate centriole disengagement with the protease Separase in mitotic cells. Strikingly, over-expression of Separase rescues centriole disengagement and cilia production in CDC20B-deficient MCCs. This work reveals the shaping of deuterosome-mediated centriole production in vertebrate MCCs, by adaptation of canonical and recently evolved cell cycle-related molecules.
Assuntos
Proteínas Cdc20/metabolismo , Centríolos/metabolismo , Cílios/metabolismo , Animais , Epêndima/metabolismo , Epiderme/metabolismo , Feminino , Humanos , Camundongos , Ligação Proteica , Separase/metabolismo , Análise de Célula Única , Transcriptoma/genética , Vertebrados/metabolismo , Xenopus laevis/embriologia , Xenopus laevis/metabolismoRESUMO
The amyloid precursor protein (APP) harbors physiological roles at synapses and is central to Alzheimer's disease (AD) pathogenesis. Evidence suggests that APP intracellular domain (AICD) could regulate synapse function, but the underlying molecular mechanisms remain unknown. We addressed AICD actions at synapses, per se, combining in vivo AICD expression, ex vivo AICD delivery or APP knock-down by in utero electroporation of shRNAs with whole-cell electrophysiology. We report a critical physiological role of AICD in controlling GluN2B-containing NMDA receptors (NMDARs) at immature excitatory synapses, via a transcription-dependent mechanism. We further show that AICD increase in mature neurons, as reported in AD, alters synaptic NMDAR composition to an immature-like GluN2B-rich profile. This disrupts synaptic signal integration, via over-activation of SK channels, and synapse plasticity, phenotypes rescued by GluN2B antagonism. We provide a new physiological role for AICD, which becomes pathological upon AICD increase in mature neurons. Thus, AICD could contribute to AD synaptic failure.