Cardiovascular diseases remain the leading cause of death worldwide; hence there is an increasing focus on developing physiologically relevant in vitro cardiovascular tissue models suitable for studying personalized medicine and pre-clinical tests. Despite recent advances, models that reproduce both tissue complexity and maturation are still limited. We have established a scaffold-free protocol to generate multicellular, beating human cardiac microtissues in vitro from hiPSCs-namely human organotypic cardiac microtissues (hOCMTs)-that show some degree of self-organization and can be cultured for long term. This is achieved by the differentiation of hiPSC in 2D monolayer culture towards cardiovascular lineage, followed by further aggregation on low-attachment culture dishes in 3D. The generated hOCMTs contain multiple cell types that physiologically compose the heart and beat without external stimuli for more than 100 days. We have shown that 3D hOCMTs display improved cardiac specification, survival and metabolic maturation as compared to standard monolayer cardiac differentiation. We also confirmed the functionality of hOCMTs by their response to cardioactive drugs in long-term culture. Furthermore, we demonstrated that they could be used to study chemotherapy-induced cardiotoxicity. Due to showing a tendency for self-organization, cellular heterogeneity, and functionality in our 3D microtissues over extended culture time, we could also confirm these constructs as human cardiac organoids (hCOs). This study could help to develop more physiologically-relevant cardiac tissue models, and represent a powerful platform for future translational research in cardiovascular biology.
- MeSH
- buněčná diferenciace fyziologie MeSH
- indukované pluripotentní kmenové buňky * MeSH
- kardiomyocyty metabolismus MeSH
- kardiovaskulární látky * metabolismus MeSH
- lidé MeSH
- protinádorové látky * metabolismus MeSH
- srdce fyziologie MeSH
- tkáňové inženýrství metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
RATIONALE: Cardiac ECM (extracellular matrix) comprises a dynamic molecular network providing structural support to heart tissue function. Understanding the impact of ECM remodeling on cardiac cells during heart failure (HF) is essential to prevent adverse ventricular remodeling and restore organ functionality in affected patients. OBJECTIVES: We aimed to (1) identify consistent modifications to cardiac ECM structure and mechanics that contribute to HF and (2) determine the underlying molecular mechanisms. METHODS AND RESULTS: We first performed decellularization of human and murine ECM (decellularized ECM) and then analyzed the pathological changes occurring in decellularized ECM during HF by atomic force microscopy, 2-photon microscopy, high-resolution 3-dimensional image analysis, and computational fluid dynamics simulation. We then performed molecular and functional assays in patient-derived cardiac fibroblasts based on YAP (yes-associated protein)-transcriptional enhanced associate domain (TEAD) mechanosensing activity and collagen contraction assays. The analysis of HF decellularized ECM resulting from ischemic or dilated cardiomyopathy, as well as from mouse infarcted tissue, identified a common pattern of modifications in their 3-dimensional topography. As compared with healthy heart, HF ECM exhibited aligned, flat, and compact fiber bundles, with reduced elasticity and organizational complexity. At the molecular level, RNA sequencing of HF cardiac fibroblasts highlighted the overrepresentation of dysregulated genes involved in ECM organization, or being connected to TGFβ1 (transforming growth factor β1), interleukin-1, TNF-α, and BDNF signaling pathways. Functional tests performed on HF cardiac fibroblasts pointed at mechanosensor YAP as a key player in ECM remodeling in the diseased heart via transcriptional activation of focal adhesion assembly. Finally, in vitro experiments clarified pathological cardiac ECM prevents cell homing, thus providing further hints to identify a possible window of action for cell therapy in cardiac diseases. CONCLUSIONS: Our multiparametric approach has highlighted repercussions of ECM remodeling on cell homing, cardiac fibroblast activation, and focal adhesion protein expression via hyperactivated YAP signaling during HF.
- MeSH
- adaptorové proteiny signální transdukční genetika metabolismus MeSH
- buněčný převod mechanických signálů MeSH
- dilatační kardiomyopatie genetika metabolismus patologie patofyziologie MeSH
- extracelulární matrix genetika metabolismus ultrastruktura MeSH
- fibroblasty metabolismus ultrastruktura MeSH
- funkce levé komory srdeční * MeSH
- infarkt myokardu genetika metabolismus patologie patofyziologie MeSH
- kultivované buňky MeSH
- lidé MeSH
- modely nemocí na zvířatech MeSH
- myokard metabolismus ultrastruktura MeSH
- myši inbrední C57BL MeSH
- pohyb buněk MeSH
- remodelace komor * MeSH
- srdeční selhání genetika metabolismus patologie patofyziologie MeSH
- studie případů a kontrol MeSH
- transkripční faktory genetika metabolismus MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- audiovizuální média MeSH
- časopisecké články MeSH
- práce podpořená grantem MeSH
The tight regulation of cytoskeleton dynamics is required for a number of cellular processes, including migration, division and differentiation. YAP-TEAD respond to cell-cell interaction and to substrate mechanics and, among their downstream effects, prompt focal adhesion (FA) gene transcription, thus contributing to FA-cytoskeleton stability. This activity is key to the definition of adult cell mechanical properties and function. Its regulation and role in pluripotent stem cells are poorly understood. Human PSCs display a sustained basal YAP-driven transcriptional activity despite they grow in very dense colonies, indicating these cells are insensitive to contact inhibition. PSC inability to perceive cell-cell interactions can be restored by tampering with Tankyrase enzyme, thus favouring AMOT inhibition of YAP function. YAP-TEAD complex is promptly inactivated when germ layers are specified, and this event is needed to adjust PSC mechanical properties in response to physiological substrate stiffness. By providing evidence that YAP-TEAD1 complex targets key genes encoding for proteins involved in cytoskeleton dynamics, we suggest that substrate mechanics can direct PSC specification by influencing cytoskeleton arrangement and intracellular tension. We propose an aberrant activation of YAP-TEAD1 axis alters PSC potency by inhibiting cytoskeleton dynamics, thus paralyzing the changes in shape requested for the acquisition of the given phenotype.
- MeSH
- adaptorové proteiny signální transdukční MeSH
- angiomotiny metabolismus MeSH
- buněčná diferenciace MeSH
- buněčné linie MeSH
- cytoskelet metabolismus MeSH
- lidé MeSH
- lidské embryonální kmenové buňky metabolismus MeSH
- mezoderm metabolismus MeSH
- signální proteiny YAP genetika metabolismus MeSH
- signální transdukce MeSH
- transkripční faktory TEA domény genetika metabolismus MeSH
- vazba proteinů MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Yes-associated protein 1 (YAP1) is a transcriptional co-activator downstream of Hippo pathway. The pathway exerts crucial roles in organogenesis and its dysregulation is associated with the spreading of different cancer types. YAP1 gene encodes for multiple protein isoforms, whose specific functions are not well defined. We demonstrate the splicing of isoform-specific mRNAs is controlled in a stage- and tissue-specific fashion. We designed expression vectors encoding for the most-represented isoforms of YAP1 with either one or two WW domains and studied their specific signaling activities in YAP1 knock-out cell lines. YAP1 isoforms display both common and unique functions and activate distinct transcriptional programs, as the result of their unique protein interactomes. By generating TEAD-based transcriptional reporter cell lines, we demonstrate individual YAP1 isoforms display unique effects on cell proliferation and differentiation. Finally, we illustrate the complexity of the regulation of Hippo-YAP1 effector in physiological and in pathological conditions of the heart.
Tumor necrosis factor-related apoptosis-inducing ligand-TRAIL-is a protein operating as a ligand capable of inducing apoptosis particularly in cancerously transformed cells, while normal healthy cells are typically nonresponsive. We have previously demonstrated that pluripotent human embryonic stem cells (hESC) are also refractory to TRAIL, even though they express all canonical components of the death receptor-induced apoptosis pathway. In this study, we have examined a capacity of DNA damage to provoke sensitivity of hESC to TRAIL. The extent of DNA damage, behavior of molecules involved in apoptosis, and response of hESC to TRAIL were investigated. The exposure of hESC to 1 μM and 2 μM concentrations of cisplatin have led to the formation of 53BP1 and γH2AX foci, indicating the presence of double-strand breaks in DNA, without affecting the expression of proteins contributing to mitochondrial membrane integrity. Interestingly, cisplatin upregulated critical components of the extrinsic apoptotic pathway-initiator caspase 8, effector caspase 3, and the cell death receptors. The observed increase of expression of the extrinsic apoptotic pathway components was sufficient to sensitize hESC to TRAIL-induced apoptosis; immense cell dying accompanied by enhanced PARP cleavage, processing of caspase 8, and full activation of caspase 3 were all observed after the treatment combining cisplatin and TRAIL. Finally, we have demonstrated the central role of caspase 8 in this process, since its downregulation abrogated the sensitizing effect of cisplatin.
- Publikační typ
- časopisecké články MeSH
Extracellular matrix (ECM) is an essential component of the tissue microenvironment, actively shaping cellular behavior. In vitro culture systems are often poor in ECM constituents, thus not allowing for naturally occurring cell-ECM interactions. This study reports on a straightforward and efficient method for the generation of ECM scaffolds from lung tissue and its subsequent in vitro application using primary lung cells. Mouse lung tissue was subjected to decellularization with 0.2% sodium dodecyl sulfate, hypotonic solutions, and DNase. Resultant ECM scaffolds were devoid of cells and DNA, whereas lung ECM architecture of alveolar region and blood and airway networks were preserved. Scaffolds were predominantly composed of core ECM and ECM-associated proteins such as collagens I-IV, nephronectin, heparan sulfate proteoglycan core protein, and lysyl oxidase homolog 1, among others. When homogenized and applied as coating substrate, ECM supported the attachment of lung fibroblasts (LFs) in a dose-dependent manner. After ECM characterization and biocompatibility tests, a novel in vitro platform for three-dimensional (3D) matrix repopulation that permits live imaging of cell-ECM interactions was established. Using this system, LFs colonized the ECM scaffolds, displaying a close-to-native morphology in intimate interaction with the ECM fibers, and showed nuclear translocation of the mechanosensor yes-associated protein (YAP), when compared with cells cultured in two dimensions. In conclusion, we developed a 3D-like culture system, by combining an efficient decellularization method with a live-imaging culture platform, to replicate in vitro native lung cell-ECM crosstalk. This is a valuable system that can be easily applied to other organs for ECM-related drug screening, disease modeling, and basic mechanistic studies.
- MeSH
- extracelulární matrix - proteiny metabolismus MeSH
- extracelulární matrix fyziologie MeSH
- fibroblasty cytologie metabolismus MeSH
- kultivované buňky MeSH
- myši inbrední C57BL MeSH
- myši inbrední ICR MeSH
- myši MeSH
- plíce cytologie metabolismus MeSH
- proteomika MeSH
- techniky in vitro MeSH
- tkáňové inženýrství metody MeSH
- tkáňové podpůrné struktury MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Living cells are constantly exposed to mechanical stimuli arising from the surrounding extracellular matrix (ECM) or from neighboring cells. The intracellular molecular processes through which such physical cues are transformed into a biological response are collectively dubbed as mechanotransduction and are of fundamental importance to help the cell timely adapt to the continuous dynamic modifications of the microenvironment. Local changes in ECM composition and mechanics are driven by a feed forward interplay between the cell and the matrix itself, with the first depositing ECM proteins that in turn will impact on the surrounding cells. As such, these changes occur regularly during tissue development and are a hallmark of the pathologies of aging. Only lately, though, the importance of mechanical cues in controlling cell function (e.g., proliferation, differentiation, migration) has been acknowledged. Here we provide a critical review of the recent insights into the molecular basis of cellular mechanotransduction, by analyzing how mechanical stimuli get transformed into a given biological response through the activation of a peculiar genetic program. Specifically, by recapitulating the processes involved in the interpretation of ECM remodeling by Focal Adhesions at cell-matrix interphase, we revise the role of cytoskeleton tension as the second messenger of the mechanotransduction process and the action of mechano-responsive shuttling proteins converging on stage and cell-specific transcription factors. Finally, we give few paradigmatic examples highlighting the emerging role of malfunctions in cell mechanosensing apparatus in the onset and progression of pathologies.
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
HMGB1 and HMGB2 proteins have been implicated in numerous cellular processes, including proliferation, differentiation, apoptosis, and tumor growth. It is unknown whether they are involved in regulating the typical functions of pluripotent human embryonic stem cells (hESCs) and/or those of the differentiated derivatives of hESCs. Using inducible, stably transfected hESCs capable of shRNA-mediated knockdown of HMGB1 and HMGB2, we provide evidence that downregulation of HMGB1 and/or HMGB2 in undifferentiated hESCs does not affect the stemness of cells and induces only minor changes to the proliferation rate, cell-cycle profile, and apoptosis. After differentiation is induced, however, the downregulation of those proteins has important effects on proliferation, apoptosis, telomerase activity, and the efficiency of differentiation toward the neuroectodermal lineage. Furthermore, those processes are affected only when one, but not both, of the two proteins is downregulated; the knockdown of both HMGB1 and HMGB2 results in a normal phenotype. Those results advance our knowledge of regulation of hESC and human neuroectodermal cell differentiation and illustrate the distinct roles of HMGB1 and HMGB2 during early human development.
- MeSH
- apoptóza genetika MeSH
- buněčná diferenciace * MeSH
- buněčná sebeobnova genetika MeSH
- buněčné linie MeSH
- buněčný cyklus genetika MeSH
- buněčný rodokmen genetika MeSH
- down regulace genetika MeSH
- histony metabolismus MeSH
- lidé MeSH
- lidské embryonální kmenové buňky cytologie metabolismus MeSH
- neurální ploténka cytologie MeSH
- proliferace buněk genetika MeSH
- protein HMGB1 metabolismus MeSH
- protein HMGB2 metabolismus MeSH
- telomerasa metabolismus MeSH
- transfekce MeSH
- tvar buňky genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Neural crest cells (NCCs) derive early in vertebrate ontogenesis from neural tube as a population of migratory cells with exquisite differentiation potential. Abnormalities in NCC behaviour are cause of debilitating diseases including cancers and a spectrum of neurocristopathies. Thanks to their multilineage differentiation capacity NCCs offer a cell source for regenerative medicine. Both these aspects make NCC biology an important issue to study, which can currently be addressed using methodologies based on pluripotent stem cells. Here we contributed to understanding the biology of human NCCs by refining the protocol for differentiation/propagation of NCClike cells from human embryonic stem cells and by characterizing the molecular and functional phenotype of such cells. Most importantly, we improved formulation of media for NCC culture, we found that poly-L-ornithine combined with fibronectin provide good support for NCC growth, we unravelled the tendency of cultured NCCs to maintain heterogeneity of CD271 expression, and we showed that NCCs derived here possess the capacity to react to BMP4 signals by dramatically up-regulating MSX1, which is linked to odontogenesis.
- MeSH
- adapalen MeSH
- biologické markery metabolismus MeSH
- buněčná diferenciace * účinky léků MeSH
- crista neuralis cytologie účinky léků metabolismus MeSH
- embryonální kmenové buňky cytologie účinky léků metabolismus MeSH
- fenotyp MeSH
- kostní morfogenetický protein 4 farmakologie MeSH
- lidé MeSH
- naftaleny metabolismus MeSH
- polymerázová řetězová reakce MeSH
- průtoková cytometrie MeSH
- transkripční faktor MSX1 metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Death ligands and their tumor necrosis factor receptor (TNFR) family receptors are the best-characterized and most efficient inducers of apoptotic signaling in somatic cells. In this study, we analyzed whether these prototypic activators of apoptosis are also expressed and able to be activated in human pluripotent stem cells. We examined human embryonic stem cells (hESC) and human-induced pluripotent stem cells (hiPSC) and found that both cell types express primarily TNF-related apoptosis-inducing ligand (TRAIL) receptors and TNFR1, but very low levels of Fas/CD95. We also found that although hESC and hiPSC contain all the proteins required for efficient induction and progression of extrinsic apoptotic signaling, they are resistant to TRAIL-induced apoptosis. However, both hESC and hiPSC can be sensitized to TRAIL-induced apoptosis by co-treatment with protein synthesis inhibitors such as the anti-leukemia drug homoharringtonine (HHT). HHT treatment led to suppression of cellular FLICE inhibitory protein (cFLIP) and Mcl-1 expression and, in combination with TRAIL, enhanced processing of caspase-8 and full activation of caspase-3. cFLIP likely represents an important regulatory node, as its shRNA-mediated down-regulation significantly sensitized hESC to TRAIL-induced apoptosis. Thus, we provide the first evidence that, irrespective of their origin, human pluripotent stem cells express canonical components of the extrinsic apoptotic system and on stress can activate death receptor-mediated apoptosis.
- MeSH
- antigeny CD95 genetika metabolismus MeSH
- apoptóza účinky léků MeSH
- buněčná diferenciace MeSH
- embryonální kmenové buňky cytologie účinky léků metabolismus MeSH
- FLIP (buněčný) antagonisté a inhibitory genetika metabolismus MeSH
- harringtoniny farmakologie MeSH
- inhibitory syntézy proteinů farmakologie MeSH
- kaspasa 3 genetika metabolismus MeSH
- kaspasa 8 genetika metabolismus MeSH
- lidé MeSH
- malá interferující RNA genetika metabolismus MeSH
- pluripotentní kmenové buňky cytologie účinky léků metabolismus MeSH
- proliferace buněk MeSH
- protein MCL-1 genetika metabolismus MeSH
- protein TRAIL genetika metabolismus farmakologie MeSH
- receptory TNF - typ I genetika metabolismus MeSH
- regulace genové exprese MeSH
- signální transdukce MeSH
- synergismus léků MeSH
- TRAIL receptory genetika metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
