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Hepatic physiology depends on the liver's complex structural composition which among others, provides high oxygen supply rates, locally differential oxygen tension, endothelial paracrine signaling, as well as residual hemodynamic shear stress to resident hepatocytes. While functional improvements were shown by implementing these factors into hepatic culture systems, direct cause-effect relationships are often not well characterized-obfuscating their individual contribution in more complex microphysiological systems. By comparing increasingly complex hepatic in vitro culture systems that gradually implement these parameters, we investigate the influence of the cellular microenvironment to overall hepatic functionality in pharmacological applications. Here, hepatocytes were modulated in terms of oxygen tension and supplementation, endothelial coculture, and exposure to fluid shear stress delineated from oxygen influx. Results from transcriptomic and metabolomic evaluation indicate that particularly oxygen supply rates are critical to enhance cellular functionality-with cellular drug metabolism remaining comparable to physiological conditions after prolonged static culture. Endothelial signaling was found to be a major contributor to differential phenotype formation known as metabolic zonation, indicated by WNT pathway activity. Lastly, oxygen-delineated shear stress was identified to direct cellular fate towards increased hepatic plasticity and regenerative phenotypes at the cost of drug metabolic functionality - in line with regenerative effects observed in vivo. With these results, we provide a systematic evaluation of critical parameters and their impact in hepatic systems. Given their adherence to physiological effects in vivo, this highlights the importance of their implementation in biomimetic devices, such as organ-on-a-chip systems. Considering recent advances in basic liver biology, direct translation of physiological structures into in vitro models is a promising strategy to expand the capabilities of pharmacological models.
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Fígado , Sistemas Microfisiológicos , Fígado/metabolismo , Hepatócitos/metabolismo , Perfilação da Expressão Gênica , Oxigênio/metabolismoRESUMO
AIM: Hepatic zonation is a physiological feature of the liver, known to be key in the regulation of the metabolism of nutrients and xenobiotics and the biotransformation of numerous substances. However, the reproduction of this phenomenon remains challenging in vitro as only part of the processes involved in the orchestration and maintenance of zonation are fully understood. The recent advances in organ-on-chip technologies, which allow for the integration of multicellular 3D tissues in a dynamic microenvironment, could offer solutions for the reproduction of zonation within a single culture vessel. METHODS: An in-depth analysis of zonation-related mechanisms observed during the coculture of human-induced pluripotent stem cell (hiPSC)-derived carboxypeptidase M-positive liver progenitor cells and hiPSC-derived liver sinusoidal endothelial cells within a microfluidic biochip was carried out. RESULTS: Hepatic phenotypes were confirmed in terms of albumin secretion, glycogen storage, CYP450 activity, and expression of specific endothelial markers such as PECAM1, RAB5A, and CD109. Further characterization of the patterns observed in the comparison of the transcription factor motif activities, the transcriptomic signature, and the proteomic profile expressed at the inlet and the outlet of the microfluidic biochip confirmed the presence of zonation-like phenomena within the biochips. In particular, differences related to Wnt/ß-catenin, transforming growth factor-ß, mammalian target of rapamycin, hypoxia-inducible factor-1, and AMP-activated protein kinase signaling, to the metabolism of lipids, and cellular remolding were observed. CONCLUSIONS: The present study shows the interest in combining cocultures of hiPSC-derived cellular models and microfluidic technologies for reproducing in vitro complex mechanisms such as liver zonation and further incites the use of those solutions for accurate reproduction of in vivo situations.
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The development of complex methods in molecular biology is a laborious, costly, iterative and often intuition-bound process where optima are sought in a multidimensional parameter space through step-by-step optimizations. The difficulty of miniaturizing reactions under the microliter volumes usually handled in multiwell plates by robots, plus the cost of the experiments, limit the number of parameters and the dynamic ranges that can be explored. Nevertheless, because of non-linearities of the response of biochemical systems to their reagent concentrations, broad dynamic ranges are necessary. Here we use a high-performance nanoliter handling platform and computer generation of liquid transfer programs to explore in quadruplicates 648 combinations of 4 parameters of a biochemical reaction, the reverse-transcription, which lead us to uncover non-linear responses, parameter interactions and novel mechanistic insights. With the increased availability of computer-driven laboratory platforms for biotechnology, our results demonstrate the feasibility and advantage of methods development based on reproducible, computer-aided exhaustive characterization of biochemical systems.
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Fenômenos Bioquímicos , Transcrição Reversa , Animais , Automação Laboratorial , Células HeLa , Humanos , Camundongos , Miniaturização , Reação em Cadeia da Polimerase , Análise de Célula ÚnicaRESUMO
Maturation of human-induced pluripotent stem cells (hiPSCs)-derived hepatocytes-like cells (HLCs) toward a complete hepatocyte phenotype remains a challenge as primitiveness patterns are still commonly observed. In this study, we propose a modified differentiation protocol for those cells which includes a prematuration in Petri dishes and a maturation in microfluidic biochip. For the first time, a large range of biomolecular families has been extracted from the same sample to combine transcriptomic, proteomic, and metabolomic analysis. After integration, these datasets revealed specific molecular patterns and highlighted the hepatic regeneration profile in biochips. Overall, biochips exhibited processes of cell proliferation and inflammation (via TGFB1) coupled with anti-fibrotic signaling (via angiotensin 1-7, ATR-2, and MASR). Moreover, cultures in this condition displayed physiological lipid-carbohydrate homeostasis (notably via PPAR, cholesterol metabolism, and bile synthesis) coupled with cell respiration through advanced oxidative phosphorylation (through the overexpression of proteins from the third and fourth complex). The results presented provide an original overview of the complex mechanisms involved in liver regeneration using an advanced in vitro organ-on-chip technology.
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Diferenciação Celular , Genômica , Hepatócitos/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Regeneração Hepática , Fígado/metabolismo , Proteômica , HumanosRESUMO
The capability to produce and maintain functional human adult hepatocytes remains one of the major challenges for the use of in-vitro models toward liver cell therapy and industrial drug-screening applications. Among the suggested strategies to solve this issue, the use of human-induced pluripotent stem cells (hiPSCs), differentiated toward hepatocyte-like cells (HLCs) is promising. In this work, we propose a 31-day long protocol, that includes a final 14-day long phase of oncostatin treatment, as opposed to a 7-day treatment which led to the formation of a hepatic tissue functional for CYP1A2, CYP2B6, CYP2C8, CYP2D6, and CYP3A4. The production of albumin, as well as bile acid metabolism and transport, were also detected. Transcriptome profile comparisons and liver transcription factors (TFs) motif dynamics revealed increased expression of typical hepatic markers such as HNF1A and of important metabolic markers like PPARA. The performed analysis has allowed for the extraction of potential targets and pathways which would allow enhanced hepatic maturation in-vitro. From this investigation, NRF1 and SP3 appeared as transcription factors of importance. Complex epithelial-mesenchymal transition (EMT) and mesenchymal-epithelial transition (MET) patterns were also observed during the differentiation process. Moreover, whole transcriptome analysis highlighted a response typical of the one observed in liver regeneration and hepatocyte proliferation. While a complete maturation of hepatocytes was yet to be obtained, the results presented in this work provide new insights into the process of liver development and highlight potential targets aimed to improve in-vitro liver regeneration.
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Diferenciação Celular/genética , Hepatócitos/citologia , Células-Tronco Pluripotentes Induzidas/citologia , Regeneração Hepática , Fígado/crescimento & desenvolvimento , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Citocromo P-450 CYP1A2/genética , Citocromo P-450 CYP2B6/genética , Citocromo P-450 CYP2C8/genética , Citocromo P-450 CYP2D6/genética , Citocromo P-450 CYP3A/genética , Avaliação Pré-Clínica de Medicamentos , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Hepatócitos/metabolismo , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Fígado/citologia , Fígado/efeitos dos fármacos , Fator 1 Nuclear Respiratório/genética , Oncostatina M/farmacologia , Fator de Transcrição Sp3/genética , Transcriptoma/efeitos dos fármacosRESUMO
In the present study, we evaluated the performance of different protocols for the hepatic differentiation of human-induced pluripotent stem cells (hiPSCs) in microfluidic biochips. Strategies for complete and partial on-chip differentiation were tested. Unlike full on-chip differentiation, the transfer of iPSCs from Petri dishes to biochips during the differentiation process produced a heterogeneous tissue with enhanced hepatic features compared with control cultures in Petri dishes. The tissue in biochips was constituted of cells expressing either stabilin-1 or albumin, while no stabilin-1 was detected in controls. Functional analysis also revealed double the production rate for albumin in biochips (about 2,000 ng per day per 106 cells). Besides this, tissues obtained in biochips and controls exhibited the metabolism of a specific bile acid. Whole transcriptome analysis with nanoCAGE exhibited a differential expression of 302 genes between control and biochip cultures and a higher degree of hepatic differentiation in biochips, together with increased promoter motif activity for typical liver transcription factors such as estrogen related receptor alpha ( ESRRA), hepatic nuclear factor 1 ( HNF1A), hepatic nuclear factor 4 ( HNF4A), transcription factor 4 ( TCF4), and CCAAT enhancer binding protein alpha ( CEBPA). Gene set enrichment analysis identified several pathways related to the extracellular matrix, tissue reorganization, hypoxia-inducible transcription factor, and glycolysis that were differentially modulated in biochip cultures. However, the presence of CK19/ALB-positive cells and the É-fetoprotein levels measured in the cultures still reflect primitive differentiation patterns. Overall, we identified key parameters for improved hepatic differentiation on-chip, including the maturation stage of hepatic progenitors, inoculation density, adhesion time, and perfusion flow rate. Optimization of these parameters further led to establish a protocol for reproducible differentiation of hiPSCs into hepatocyte-like cells in microfluidic biochips with significant improvements over Petri dish cultures.
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Diferenciação Celular , Hepatócitos , Células-Tronco Pluripotentes Induzidas , Fígado , Técnicas Analíticas Microfluídicas , Nicho de Células-Tronco , Regulação da Expressão Gênica , Células Hep G2 , Hepatócitos/citologia , Hepatócitos/metabolismo , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Fígado/citologia , Fígado/metabolismo , Fatores de Transcrição/metabolismoRESUMO
Cavitation bubbles induce impulsive forces on surrounding substrates, particles, or surfaces. Even though cavitation is a traditional topic in fluid mechanics, current understanding and studies do not capture the effect of cavitation on suspended objects in fluids. In the present work, the dynamics of a spherical particle due to a cavitation bubble is experimentally characterized and compared with an analytical model. Three phases are observed: the growth of the bubble where the particle is pushed away, its collapse where the particle approaches the bubble, and a longer time scale postcollapse where the particle continues to move toward the collapsed bubble. The particle motion in the longer time scale presumably results from the asymmetric cavitation evolution at an earlier time. Our theory considering the asymmetric bubble dynamics shows that the particle velocity strongly depends on the distance from the bubble as an inverse-fourth-power law, which is in good agreement with our experimentation. This study sheds light on how small free particles respond to cavitation bubbles in fluids.
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Microbolhas , Modelos Teóricos , HidrodinâmicaRESUMO
Inflammation is a powerful response of the immune system against invading pathogens, and must be cancelled when unneeded or otherwise death inevitably follows. In macrophages, the anti-inflammatory response (AIR) is driven by STAT3 upon IL-10 signaling. The role of STAT3 is to stimulate the expression of specific genes that in-turn suppress the transcription of proinflammatory genes. Here we describe a systematic approach to identify the elusive STAT3-controlled effectors of the AIR. In vivo STAT3-binding sites were identified by ChIP-seq, coupled to expression analysis by RNA-seq, both in resting and IL-10-treated peritoneal macrophages. We report the genomic targets of STAT3 and show that STAT3's transcriptional program during the AIR is highly specific to IL-10-stimulated macrophages, that STAT3 is a positive transcriptional regulator, and we predict severalputative AIR factors that merit further investigation. This is the first in-depth study of the AIR by next-generation sequencing and provides an unprecedented degree of detail into this fundamental physiologic response.
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Anti-Inflamatórios/metabolismo , Mapeamento Cromossômico , Inflamação/genética , Macrófagos Peritoneais/metabolismo , Fator de Transcrição STAT3/metabolismo , Animais , Sítios de Ligação/genética , Biomarcadores Farmacológicos/análise , Biomarcadores Farmacológicos/metabolismo , Mapeamento Cromossômico/métodos , Análise por Conglomerados , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/efeitos dos fármacos , Imunidade Celular/efeitos dos fármacos , Imunidade Celular/genética , Imunidade Celular/fisiologia , Inflamação/metabolismo , Interleucina-10/farmacologia , Macrófagos Peritoneais/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Análise em Microsséries , Transcriptoma/genéticaRESUMO
Type 2 diabetes (T2D) is posing a serious public health concern with a considerable impact on human life and health expenditures worldwide. The disease develops when insulin plasma level is insufficient for coping insulin resistance, caused by the decline of pancreatic ß-cell function and mass. In ß-cells, the lipotoxicity exerted by saturated free fatty acids in particular palmitate (PA), which is chronically elevated in T2D, plays a major role in ß-cell dysfunction and mass. However, there is a lack of human relevant in vitro model to identify the underlying mechanism through which palmitate induces ß-cell failure. In this frame, we have previously developed a cutting-edge 3D spheroid model of ß-like cells derived from human induced pluripotent stem cells. In the present work, we investigated the signaling pathways modified by palmitate in ß-like cells derived spheroids. When compared to the 2D monolayer cultures, the transcriptome analysis (FDR set at 0.1) revealed that the 3D spheroids upregulated the pancreatic markers (such as GCG, IAPP genes), lipids metabolism and transporters (CD36, HMGSC2 genes), glucose transporter (SLC2A6). Then, the 3D spheroids are exposed to PA 0.5 mM for 72 h. The differential analysis demonstrated that 32 transcription factors and 135 target genes were mainly modulated (FDR set at 0.1) including the upregulation of lipid and carbohydrates metabolism (HMGSC2, LDHA, GLUT3), fibrin metabolism (FGG, FGB), apoptosis (CASP7). The pathway analysis using the 135 selected targets extracted the fibrin related biological process and wound healing in 3D PA treated conditions. An overall pathway gene set enrichment analysis, performed on the overall gene set (with pathway significance cutoff at 0.2), highlighted that PA perturbs the citrate cycle, FOXO signaling and Hippo signaling as observed in human islets studies. Additional RT-PCR confirmed induction of inflammatory (IGFBP1, IGFBP3) and cell growth (CCND1, Ki67) pathways by PA. All these changes were associated with unaffected glucose-stimulated insulin secretion (GSIS), suggesting that they precede the defect of insulin secretion and death induced by PA. Overall, we believe that our data demonstrate the potential of our spheroid 3D islet-like cells to investigate the pancreatic-like response to diabetogenic environment.
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Perfilação da Expressão Gênica , Células-Tronco Pluripotentes Induzidas , Células Secretoras de Insulina , Ácido Palmítico , Esferoides Celulares , Humanos , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/efeitos dos fármacos , Esferoides Celulares/efeitos dos fármacos , Esferoides Celulares/metabolismo , Ácido Palmítico/farmacologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Células-Tronco Pluripotentes Induzidas/citologia , Perfilação da Expressão Gênica/métodos , Transcriptoma/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/genéticaRESUMO
Availability of hepatic tissue for the investigation of metabolic processes is severely limited. While primary hepatocytes or animal models are widely used in pharmacological applications, a change in methodology towards more sustainable and ethical assays is highly desirable. Stem cell derived hepatic cells are generally regarded as a viable alternative for the above model systems, if current limitations in functionality and maturation can be overcome. By combining microfluidic organ-on-a-chip technology with individually differentiated, multicellular hepatic tissue fractions, we aim to improve overall functionality of hepatocyte-like cells, as well as evaluate cellular composition and interactions with non-parenchymal cell populations towards the formation of mature liver tissue. Utilizing a multi-omic approach, we show the improved maturation profiles of hepatocyte-like cells maintained in a dynamic microenvironment compared to standard tissue culture setups without continuous perfusion. In order to evaluate the resulting tissue, we employ single cell sequencing to distinguish formed subpopulations and spatial localization. While cellular input was strictly defined based on established differentiation protocols of parenchyma, endothelial and stellate cell fractions, resulting hepatic tissue was shown to comprise a complex mixture of epithelial and non-parenchymal fractions with specific local enrichment of phenotypes along the microchannel. Following this approach, we show the importance of passive, paracrine developmental processes in tissue formation. Using such complex tissue models is a crucial first step to develop stem cell-derivedin vitrosystems that can compare functionally with currently used pharmacological and toxicological applications.
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Hepatócitos , Fígado , Animais , Células-Tronco , Diferenciação CelularRESUMO
Despite the routine application of RNA-seq technology to profile cellular transcriptomes and report novel splice variants, the identification and validation of new transcripts remain underexplored. We prepared two RNA-seq libraries from resting and T cell receptor-stimulated mouse CD4(+) T cells. Transcripts unknown to Ensembl represent as much as 5% of the assembled transcripts and are robustly expressed but do not show the same degree of evolutionary conservation or exon distribution of known transcripts, or of novel splice isoforms. Here we present a straightforward and generally applicable computational/experimental workflow that we apply to characterise and experimentally validate 23 mouse transcripts from the RNA-seq libraries that were uncharacterised by Ensembl. Of these, 7 are not supported by any transcript database and therefore are likely to encode new messages. Furthermore, we also report the fast up-regulation of important regulatory molecules only 4 h post-stimulation of the T cell receptor, which calls for a more detailed investigation into early CD4(+) T cell activation mechanisms.
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Linfócitos T CD4-Positivos/metabolismo , Evolução Molecular , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica/imunologia , Análise de Sequência de RNA/métodos , Animais , Biologia Computacional/métodos , Biblioteca Gênica , Camundongos , Reação em Cadeia da Polimerase em Tempo RealRESUMO
Correction for 'Generation of ß-like cell subtypes from differentiated human induced pluripotent stem cells in 3D spheroids' by Lisa Morisseau et al., Mol. Omics, 2023, https://doi.org/10.1039/d3mo00050h.
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Since the identification of four different pancreatic ß-cell subtypes and bi-hormomal cells playing a role in the diabetes pathogenesis, the search for in vitro models that mimics such cells heterogeneity became a key priority in experimental and clinical diabetology. We investigated the potential of human induced pluripotent stem cells to lead to the development of the different ß-cells subtypes in honeycomb microwell-based 3D spheroids. The glucose-stimulated insulin secretion confirmed the spheroids functionality. Then, we performed a single cell RNA sequencing of the spheroids. Using a knowledge-based analysis with a stringency on the pancreatic markers, we extracted the ß-cells INS+/UCN3+ subtype (11%; ß1-like cells), the INS+/ST8SIA1+/CD9- subtype (3%, ß3-like cells) and INS+/CD9+/ST8SIA1-subtype (1%; ß2-like cells) consistently with literature findings. We did not detect the INS+/ST8SIA1+/CD9+ cells (ß4-like cells). Then, we also identified four bi-hormonal cells subpopulations including δ-like cells (INS+/SST+, 6%), γ-like cells (INS+/PPY+, 3%), α-like-cells (INS+/GCG+, 6%) and ε-like-cells (INS+/GHRL+, 2%). Using data-driven clustering, we extracted four progenitors' subpopulations (with the lower level of INS gene) that included one population highly expressing inhibin genes (INHBA+/INHBB+), one population highly expressing KCNJ3+/TPH1+, one population expressing hepatocyte-like lineage markers (HNF1A+/AFP+), and one population expressing stem-like cell pancreatic progenitor markers (SOX2+/NEUROG3+). Furthermore, among the cycling population we found a large number of REST+ cells and CD9+ cells (CD9+/SPARC+/REST+). Our data confirm that our differentiation leads to large ß-cell heterogeneity, which can be used for investigating ß-cells plasticity under physiological and pathophysiological conditions.
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Células-Tronco Pluripotentes Induzidas , Células Secretoras de Insulina , Humanos , Diferenciação Celular/genética , Células Secretoras de Insulina/metabolismo , Pâncreas/metabolismo , Secreção de InsulinaRESUMO
Functional differentiation of pancreatic like tissue from human induced pluripotent stem cells is one of the emerging strategies to achieve an in vitro pancreas model. Here, we propose a protocol to cultivate hiPSC-derived ß-like-cells coupling spheroids and microfluidic technologies to improve the pancreatic lineage maturation. The protocol led to the development of spheroids producing the C-peptide and containing cells positive to insulin and glucagon. In order to further characterize the cellular and molecular profiles, we performed full transcriptomics and metabolomics analysis. The omics analysis confirmed the activation of key transcription factors together with the upregulation of genes and the presence of metabolites involved in functional pancreatic tissue development, extracellular matrix remodeling, lipid and fatty acid metabolism, and endocrine hormone signaling. When compared to static 3D honeycomb cultures, dynamic 3D biochip cultures contributed to increase specifically the activity of the HIF transcription factor, to activate the calcium activated cation channels, to enrich the glucagon and insulin pathways and glycolysis/gluconeogenesis, and to increase the secretion of serotonin, glycerol and glycerol-3-phosphate at the metabolic levels.
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Células-Tronco Pluripotentes Induzidas , Peptídeo C/metabolismo , Cálcio/metabolismo , Diferenciação Celular/genética , Ácidos Graxos/metabolismo , Glucagon/metabolismo , Glicerol/metabolismo , Humanos , Dispositivos Lab-On-A-Chip , Lipídeos , Metaboloma , Pâncreas/metabolismo , Fosfatos/metabolismo , Serotonina/metabolismo , Fatores de Transcrição/metabolismo , TranscriptomaRESUMO
Interactions between the different liver cell types are critical to the maintenance or induction of their function in vitro. In this work, human-induced Pluripotent Stem Cells (hiPSCs)-derived Liver Sinusoidal Endothelial Cells (LSECs) and Hepatocytes-Like Cells (HLCs) were cultured and matured in a microfluidic environment. Both cell populations were differentiated in Petri dishes, detached, and inoculated in microfluidic biochips. In cocultures of both cell types, the tissue has exhibited a higher production of albumin (3.19 vs 5.31 µg/mL/106 cells in monocultures and cocultures) as well as a higher inducibility CYP450 over monocultures of HLCs. Tubular-like structures composed of LSECs and positive for the endothelial marker PECAM1, as well as a tissue more largely expressing Stabilin-2 were detected in cocultures only. In contrast, monocultures exhibited no network and less specific endothelial markers. The transcriptomic analysis did not reveal a marked difference between the profiles of both culture conditions. Nevertheless, the analysis allowed us to highlight different upstream regulators in cocultures (SP1, EBF1, and GATA3) and monocultures (PML, MECP2, and NRF1). In cocultures, the multi-omics dataset after 14 days of maturation in biochips has shown the activation of signaling related to hepatic maturation, angiogenesis, and tissue repair. In this condition, inflammatory signaling was also found to be reduced when compared to monocultures as illustrated by the activation of NFKB and by the detection of several cytokines involved in tissue injury in the latter. Finally, the extracted biological processes were discussed regarding the future development of a new generation of human in vitro hepatic models.
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Liver Sinusoidal Endothelial Cells (LSECs) are an important component of the liver as they compose the microvasculature which allows the supply of oxygen, blood, and nutrients. However, maintenance of these cells in vitro remains challenging as they tend to rapidly lose some of their characteristics such as fenestration or as their immortalized counterparts present poor characteristics. In this work, human induced pluripotent stem cells (hiPSCs) have been differentiated toward an LSEC phenotype. After differentiation, the RNA quantification allowed demonstration of high expression of specific vascular markers (CD31, CD144, and STAB2). Immunostaining performed on the cells was found to be positive for both Stabilin-1 and Stabilin-2. Whole transcriptome analysis performed with the nanoCAGE method further confirmed the overall vascular commitment of the cells. The gene expression profile revealed the upregulation of the APLN, LYVE1, VWF, ESAM and ANGPT2 genes while VEGFA appeared to be downregulated. Analysis of promoter motif activities highlighted several transcription factors (TFs) of interest in LSECs (IRF2, ERG, MEIS2, SPI1, IRF7, WRNIP1, HIC2, NFIX_NFIB, BATF, and PATZ1). Based on this investigation, we compiled the regulatory network involving the relevant TFs, their target genes as well as their related signaling pathways. The proposed hiPSC-derived LSEC model and its regulatory network were then confirmed by comparing the experimental data to primary human LSEC reference datasets. Thus, the presented model appears as a promising tool to generate more complex in vitro liver multi-cellular tissues.
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Perfilação da Expressão Gênica/métodos , Células-Tronco Pluripotentes Induzidas/citologia , Fígado/citologia , Diferenciação Celular , Células Cultivadas , Células Endoteliais/química , Células Endoteliais/citologia , Redes Reguladoras de Genes , Humanos , Células-Tronco Pluripotentes Induzidas/química , Fígado/química , Nanotecnologia , Sequenciamento do ExomaRESUMO
Most of the children placed in child welfare residential care have experienced complex traumas linked to various forms of abuse and neglect, which have many important developmental impacts. Research shows that maltreatment is associated with increased aggression and disruptive behavior, internalizing difficulties, violence towards self and others, sexualized behaviors, academic difficulties, and early drug abuse. These experiences also negatively affect the attachment system and the mentalization process of the child. Consequently, working with this population represents a challenge for child care workers. This article describes a mentalization-based training program for child care workers who care for children aged six to 12 years old. First, the general framework of the training program is presented. Then, some of the therapeutic strategies used to improve the children's mentalizing capacity are described. Those strategies are adapted to the psychic functioning level of the child. Finally, a summary of a preliminary study of the program's efficacy are presented. This work suggests that mentalization-based interventions might represent a valuable approach in child welfare residential care.
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The liver zonation is an important phenomenon characterized by a gradient of several functions along the liver acinus. However, this gradient remains difficult to reproduce in in-vitro conditions, making the obtention of an in-vitro method to recapitulate the liver zonation a challenging issue. In this study, we evaluated the spatial evolution of the transcriptome profile of human induced pluripotent stem cells (hiPSCs) differentiated toward hepatocytes-like cells (HLCs) phenotype in a microfluidic biochip environment. Cells collected at the inlet of the biochip, where the oxygen concentration is higher, were identified by the expression of genes involved in metabolic pathways related to cellular reorganization and cell proliferation. Cells collected in the middle and at the outlet of the biochips, where oxygen concentrations are lower, were characterized by the upregulation of genes involved in cellular detoxification processes (CYP450), PPAR signaling or arginine biosynthesis. A subset of 16 transcription factors (TFs) was extracted and identified as upstream regulators to HNF1A and PPARA. These TFs are also known as regulators to target genes engaged in the Wnt/ßcatenin pathway, in the TGFß/BMP/SMAD signaling, in the transition between epithelial mesenchymal transition (EMT) and mesenchymal epithelial transition (MET), in the homeostasis of lipids, bile acids and carbohydrates homeostasis, in drug metabolism, in the estrogen processing and in the oxidative stress response. Overall, the analysis allowed to confirm a partial zonation-like pattern in hiPSCs-derived HLCs in the microfluidic biochip environment. These results provide important insights into the reproduction of liver zonation in-vitro for a better understanding of the phenomenon.
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Hepatócitos , Células-Tronco Pluripotentes Induzidas , Fígado , Técnicas Analíticas Microfluídicas/métodos , Transcriptoma/genética , Diferenciação Celular , Células Cultivadas , Hepatócitos/citologia , Hepatócitos/metabolismo , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Fígado/citologia , Fígado/metabolismo , Nanoestruturas/química , Engenharia TecidualRESUMO
BACKGROUND: Retinoid Receptors are involved in development and cell homeostasis. Alterations of their expressions have been observed in lung cancer. However, retinoid chemoprevention trials in populations at risk to develop such tumors have failed. Therefore, the pertinence of new clinical trials using second generation retinoid requires prior better understanding of retinoid signalling. This is our aim when validating extensively research tools, focused on Retinoic Acid Receptor beta, whose major role in lung cancer is documented. METHODS: Biocomputing was used to assess the genomic organization of RAR beta. Its putative RAR-beta1' promoter features were investigated experimentally. Specific measures realized, with qRT-PCR Syber Green assays and a triplex of Taqman probes, were extensively validated to establish Retinoid Receptors mRNAs reference values for in vivo normal human bronchial cells, lung tumors and cell lines. Finally, a pan-RAR-beta antibody was generated and extensively validated by western-blot and immunoprecipitation. RESULTS: No promoter-like activity was found for RAR-beta1'. RAR-beta2 mRNAs increase signs the normal differentiation of the human bronchial epithelium while a decrease is observed in most lung cancer cell lines. Accordingly, it is also, along with RXR beta, down-regulated in lung tumors. When using nuclear extracts of BEAS-2B and normal lung cells, only the RAR-beta2 long protein isoform was recognized by our antibody. CONCLUSION: Rigorous samples processing and extensive biocomputing, were the key factors for this study. mRNA reference values and validated tools can now be used to advance researches on retinoid signalling in the lung.
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Perfilação da Expressão Gênica/métodos , Pulmão/metabolismo , RNA Mensageiro/análise , Receptores do Ácido Retinoico/genética , Transdução de Sinais/genética , Sequência de Bases , Western Blotting , Perfilação da Expressão Gênica/normas , Humanos , Imunoprecipitação , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Dados de Sequência Molecular , Regiões Promotoras Genéticas , Isoformas de Proteínas/metabolismo , RNA Mensageiro/genética , Receptores do Ácido Retinoico/metabolismo , Valores de Referência , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
We investigated the human induced pluripotent stem cells (hiPSCs) during a sequential in vitro step-by-step differentiation into hepatocyte-like cells (HLCs) using nanoCAGE, a method for promoters, transcription factors, and transcriptome analysis. Specific gene clusters reflected the different steps of the hepatic differentiation. The proliferation step was characterized by a typical cell cycle and DNA replication. The hepatic endoderm and the HLC steps were marked by a common signature including cell interactions with extracellular matrix (ECM), lipoproteins and hepatic biomarkers (such as albumin and alpha-fetoprotein). The specific HLC profile was characterized by important transcription factors such as HIF1A, JUN, MAF, KLF6, BMP4 and with a larger expression of genes related to Wnt signaling, extracellular matrix, lipid metabolism, urea cycle, drugs, and solute transporters. HLC profile was also characterized by the activation of upstream regulators such as HNF1A, MEIS2, NFIX, WRNIP1, SP4, TAL1. Their regulatory networks highlighted HNF4a as a bridge and linked them to important processes such as EMT-MET transitions, ECM remodeling and liver development pathways (HNF3, PPARA signaling, iron metabolism) along the different steps of differentiation.