scholarly journals ECM deposition is driven by caveolin1-dependent regulation of exosomal biogenesis and cargo sorting

2018 ◽  
Author(s):  
Lucas Albacete-Albacete ◽  
Inmaculada Navarro-Lérida ◽  
Juan Antonio Lopez ◽  
Inés Martín-Padura ◽  
Alma M. Astudillo ◽  
...  
Keyword(s):  
Cell Fate ◽  
Tumour Cell ◽  
Molecular Mechanisms ◽  
Tumour Progression ◽  
Cell Communication ◽  
Cell Types ◽  
Stromal Fibroblast ◽  
Tumour Stroma ◽  
Cargo Sorting

ABSTRACTThe composition and physical properties of the extracellular matrix (ECM) critically influence tumour cell behaviour, and ECM deposition and remodelling by stromal fibroblast populations is therefore pivotal for tumour progression. The molecular mechanisms by which stromal and tumour cell populations regulate ECM layering are poorly understood. Tumour-stroma interaction is critically dependent on cell-cell communication mediated by exosomes, small vesicles secreted by most cell types and generated within multivesicular bodies (MVBs). Here, we show that caveolin-1 (Cav1), an essential regulator of stromal remodelling and tumour cell fate, plays a central role in modulating both exosome biogenesis and exosomal protein cargo sorting through cholesterol-dependent mechanisms. Quantitative proteomics profiling revealed that a major share of Cav1-dependent exosomal cargoes are compsed of ECM proteins, one of the most important components being tenascin-C (TnC). Comparative functional assays demonstrated that Cav1 is required for fibroblast-derived exosomes to depose ECM and promote tumour cell invasiveness. Exosomes purified from Cav1WT cells, but not those from Cav1-null cells, were able to nucleate distant stromal niches in different organs in vivo. These findings suggest a key role for Cav1 as a cholesterol rheostat in MVBs, and seems to determine ECM deposition by eliciting ECM component sorting into specific exosome pools. These results, together with previous work, support a model in which Cav1 is a central regulatory hub for tumour-stroma interactions through a novel exosome-dependent ECM deposition mechanism.

Advances and Challenges in Kidney Organoids

2021 ◽  
Vol 16 ◽  
Author(s):  
Vikram Sabapathy ◽  
Gabrielle Costlow ◽  
Rajkumar Venkatadri ◽  
Murat Dogan ◽  
Sanjay Kumar ◽  
...  
Keyword(s):  
Cell Fate ◽  
Pluripotent Stem Cells ◽  
Molecular Mechanisms ◽  
Cell Types ◽  
Complex Structures ◽  
Cell Culture Systems ◽  
Epigenetic Signatures ◽  
Kidney Organoids

: The advent of organoids has renewed researcher's interest in in vitro cell culture systems. A wide variety of protocols, primarily utilizing pluripotent stem cells, are under development to improve organoid generation to mimic organ development. The complexity of organoids generated is greatly influenced based on the method used. Understanding the process of kidney organoid formation gives developmental insights into how renal cells form, mature, and interact with the adjacent cells to form specific spatiotemporal structural patterns. This knowledge can bridge the gaps in understanding in vivo renal developmental processes. Evaluating genetic and epigenetic signatures in specialized cell types can help interpret the molecular mechanisms governing cell fate. In addition, development in single-cell RNA sequencing and 3D bioprinting and microfluidic technologies has led to better identification and understanding of a variety of cell types during differentiation and designing of complex structures to mimic the conditions in vivo. While several reviews have highlighted the application of kidney organoids, there is no comprehensive review of various methodologies specifically focusing on the kidney organoids. This review summarizes the updated differentiation methodologies, applications, and challenges associated with kidney organoids. Here we have comprehensively collated all the different variables influencing the organoid generation.

scholarly journals ECM deposition is driven by caveolin-1–dependent regulation of exosomal biogenesis and cargo sorting

2020 ◽  
Vol 219 (11) ◽  
Author(s):  
Lucas Albacete-Albacete ◽  
Inmaculada Navarro-Lérida ◽  
Juan Antonio López ◽  
Inés Martín-Padura ◽  
Alma M. Astudillo ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Cell Communication ◽  
Tumor Stroma ◽  
Cholesterol Content ◽  
Deposition Mechanism ◽  
Caveolin 1 ◽  
Exosome Biogenesis ◽  
Exosomal Sorting ◽  
Cargo Sorting

The composition and physical properties of the extracellular matrix (ECM) critically influence tumor progression, but the molecular mechanisms underlying ECM layering are poorly understood. Tumor–stroma interaction critically depends on cell communication mediated by exosomes, small vesicles generated within multivesicular bodies (MVBs). We show that caveolin-1 (Cav1) centrally regulates exosome biogenesis and exosomal protein cargo sorting through the control of cholesterol content at the endosomal compartment/MVBs. Quantitative proteomics profiling revealed that Cav1 is required for exosomal sorting of ECM protein cargo subsets, including Tenascin-C (TnC), and for fibroblast-derived exosomes to efficiently deposit ECM and promote tumor invasion. Cav1-driven exosomal ECM deposition not only promotes local stromal remodeling but also the generation of distant ECM-enriched stromal niches in vivo. Cav1 acts as a cholesterol rheostat in MVBs, determining sorting of ECM components into specific exosome pools and thus ECM deposition. This supports a model by which Cav1 is a central regulatory hub for tumor–stroma interactions through a novel exosome-dependent ECM deposition mechanism.

scholarly journals Lactate Metabolism and Satellite Cell Fate

2020 ◽  
Vol 11 ◽  
Author(s):  
Minas Nalbandian ◽  
Zsolt Radak ◽  
Masaki Takeda
Keyword(s):  
Skeletal Muscle ◽  
Cell Fate ◽  
Cell Communication ◽  
Cell Types ◽  
Short Review ◽  
Skeletal Muscle Regeneration ◽  
Metabolic Switch ◽  
Adult Skeletal Muscle

Lactate is one of the metabolic products of glycolysis. It is widely accepted as an important energy source for many cell types and more recently has been proposed to actively participate in cell-cell communication. Satellite cells (SCs), which are adult skeletal muscle stem cells, are the main players of the skeletal muscle regeneration process. Recent studies have proposed a metabolic switch to increase glycolysis in activated SCs. Moreover, lactate has been shown to affect SCs and myoblasts in vivo and in vitro. In this short review, we describe how metabolic variations relate with SC fate (quiescence, activation, proliferation, migration, differentiation, fusion, and self-renewal), as well as discuss possible relationships between lactate as a metabolite and as a signaling molecule affecting SC fate.

scholarly journals From Clones to Buds and Branches: The Use of Lung Organoids to Model Branching Morphogenesis Ex Vivo

2021 ◽  
Vol 9 ◽  
Author(s):  
Ana Ivonne Vazquez-Armendariz ◽  
Susanne Herold
Keyword(s):  
Cell Fate ◽  
Molecular Mechanisms ◽  
Ex Vivo ◽  
3D Culture ◽  
Cell Types ◽  
Branching Morphogenesis ◽  
Cell Fate Decisions ◽  
Culture Systems

Three-dimensional (3D) organoid culture systems have rapidly emerged as powerful tools to study organ development and disease. The lung is a complex and highly specialized organ that comprises more than 40 cell types that offer several region-specific roles. During organogenesis, the lung goes through sequential and morphologically distinctive stages to assume its mature form, both structurally and functionally. As branching takes place, multipotent epithelial progenitors at the distal tips of the growing/bifurcating epithelial tubes progressively become lineage-restricted, giving rise to more differentiated and specialized cell types. Although many cellular and molecular mechanisms leading to branching morphogenesis have been explored, deeper understanding of biological processes governing cell-fate decisions and lung patterning is still needed. Given that these distinct processes cannot be easily analyzedin vivo, 3D culture systems have become a valuable platform to study organogenesisin vitro. This minireview focuses on the current lung organoid systems that recapitulate developmental events occurring before and during branching morphogenesis. In addition, we also discuss their limitations and future directions.

scholarly journals PCGF1 promotes epigenetic activation of stemness markers and colorectal cancer stem cell enrichment

2021 ◽  
Vol 12 (7) ◽  
Author(s):  
Guangyu Ji ◽  
Wenjuan Zhou ◽  
Jingyi Du ◽  
Juan Zhou ◽  
Dong Wu ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Stem Cell ◽  
Cancer Progression ◽  
Molecular Mechanisms ◽  
Tumour Progression ◽  
Stem Cell Markers ◽  
Epigenetic Regulator ◽  
Cell Enrichment ◽  
Histone Trimethylation

AbstractColorectal cancer (CRC) stem cells are resistant to cancer therapy and are therefore responsible for tumour progression after conventional therapy fails. However, the molecular mechanisms underlying the maintenance of stemness are poorly understood. In this study, we identified PCGF1 as a crucial epigenetic regulator that sustains the stem cell-like phenotype of CRC. PCGF1 expression was increased in CRC and was significantly correlated with cancer progression and poor prognosis in CRC patients. PCGF1 knockdown inhibited CRC stem cell proliferation and CRC stem cell enrichment. Importantly, PCGF1 silencing impaired tumour growth in vivo. Mechanistically, PCGF1 bound to the promoters of CRC stem cell markers and activated their transcription by increasing the H3K4 histone trimethylation (H3K4me3) marks and decreasing the H3K27 histone trimethylation (H3K27me3) marks on their promoters by increasing expression of the H3K4me3 methyltransferase KMT2A and the H3K27me3 demethylase KDM6A. Our findings suggest that PCGF1 is a potential therapeutic target for CRC treatment.

scholarly journals Neuron-specific activation of necroptosis signaling in multiple sclerosis cortical grey matter

2021 ◽  
Vol 141 (4) ◽  
pp. 585-604 ◽  
Author(s):  
Carmen Picon ◽  
Anusha Jayaraman ◽  
Rachel James ◽  
Catriona Beck ◽  
Patricia Gallego ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Signaling Pathway ◽  
Cortical Neurons ◽  
Grey Matter ◽  
Molecular Mechanisms ◽  
Fold Increase ◽  
Cell Types ◽  
Meningeal Inflammation ◽  
Cortical Grey Matter

AbstractSustained exposure to pro-inflammatory cytokines in the leptomeninges is thought to play a major role in the pathogenetic mechanisms leading to cortical pathology in multiple sclerosis (MS). Although the molecular mechanisms underlying neurodegeneration in the grey matter remain unclear, several lines of evidence suggest a prominent role for tumour necrosis factor (TNF). Using cortical grey matter tissue blocks from post-mortem brains from 28 secondary progressive MS subjects and ten non-neurological controls, we describe an increase in expression of multiple steps in the TNF/TNF receptor 1 signaling pathway leading to necroptosis, including the key proteins TNFR1, FADD, RIPK1, RIPK3 and MLKL. Activation of this pathway was indicated by the phosphorylation of RIPK3 and MLKL and the formation of protein oligomers characteristic of necrosomes. In contrast, caspase-8 dependent apoptotic signaling was decreased. Upregulation of necroptotic signaling occurred predominantly in macroneurons in cortical layers II–III, with little expression in other cell types. The presence of activated necroptotic proteins in neurons was increased in MS cases with prominent meningeal inflammation, with a 30-fold increase in phosphoMLKL+ neurons in layers I–III. The density of phosphoMLKL+ neurons correlated inversely with age at death, age at progression and disease duration. In vivo induction of chronically elevated TNF and INFγ levels in the CSF in a rat model via lentiviral transduction in the meninges, triggered inflammation and neurodegeneration in the underlying cortical grey matter that was associated with increased neuronal expression of TNFR1 and activated necroptotic signaling proteins. Exposure of cultured primary rat cortical neurons to TNF induced necroptosis when apoptosis was inhibited. Our data suggest that neurons in the MS cortex are dying via TNF/TNFR1 stimulated necroptosis rather than apoptosis, possibly initiated in part by chronic meningeal inflammation. Neuronal necroptosis represents a pathogenetic mechanism that is amenable to therapeutic intervention at several points in the signaling pathway.

scholarly journals Filopodyan: An open-source pipeline for the analysis of filopodia

2017 ◽  
Vol 216 (10) ◽  
pp. 3405-3422 ◽  
Author(s):  
Vasja Urbančič ◽  
Richard Butler ◽  
Benjamin Richier ◽  
Manuel Peter ◽  
Julia Mason ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Dynamic Properties ◽  
Cell Types ◽  
Molecular Heterogeneity ◽  
Interactive Editing ◽  
Motile Cells ◽  
Different Cell Types ◽  
Neuronal Growth Cones

Filopodia have important sensory and mechanical roles in motile cells. The recruitment of actin regulators, such as ENA/VASP proteins, to sites of protrusion underlies diverse molecular mechanisms of filopodia formation and extension. We developed Filopodyan (filopodia dynamics analysis) in Fiji and R to measure fluorescence in filopodia and at their tips and bases concurrently with their morphological and dynamic properties. Filopodyan supports high-throughput phenotype characterization as well as detailed interactive editing of filopodia reconstructions through an intuitive graphical user interface. Our highly customizable pipeline is widely applicable, capable of detecting filopodia in four different cell types in vitro and in vivo. We use Filopodyan to quantify the recruitment of ENA and VASP preceding filopodia formation in neuronal growth cones, and uncover a molecular heterogeneity whereby different filopodia display markedly different responses to changes in the accumulation of ENA and VASP fluorescence in their tips over time.

scholarly journals Assessment of phagocytic activity in live macrophages-tumor cells co-cultures by Confocal and Nomarski Microscopy

2017 ◽  
Vol 2 (1) ◽  
Author(s):  
Dalia Martinez-Marin ◽  
Courtney Jarvis ◽  
Thomas Nelius ◽  
Stéphanie Filleur
Keyword(s):  
Tumor Microenvironment ◽  
Tumor Cells ◽  
Phagocytic Activity ◽  
Molecular Mechanisms ◽  
Cell Types ◽  
Functional Assay ◽  
Loss Of Function ◽  
Multiple Cancer

Abstract Macrophages have been recognized as the main inflammatory component of the tumor microenvironment. Although often considered as beneficial for tumor growth and disease progression, tumor-associated macrophages have also been shown to be detrimental to the tumor depending on the tumor microenvironment. Therefore, understanding the molecular interactions between macrophages and tumor cells in relation to macrophages functional activities such as phagocytosis is critical for a better comprehension of their tumor-modulating action. Still, the characterization of these molecular mechanisms in vivo remains complicated due to the extraordinary complexity of the tumor microenvironment and the broad range of tumor-associated macrophage functions. Thus, there is an increasing demand for in vitro methodologies to study the role of cell–cell interactions in the tumor microenvironment. In the present study, we have developed live co-cultures of macrophages and human prostate tumor cells to assess the phagocytic activity of macrophages using a combination of Confocal and Nomarski Microscopy. Using this model, we have emphasized that this is a sensitive, measurable, and highly reproducible functional assay. We have also highlighted that this assay can be applied to multiple cancer cell types and used as a selection tool for a variety of different types of phagocytosis agonists. Finally, combining with other studies such as gain/loss of function or signaling studies remains possible. A better understanding of the interactions between tumor cells and macrophages may lead to the identification of new therapeutic targets against cancer.

scholarly journals The Winding Road of Cardiac Regeneration—Stem Cell Omics in the Spotlight

Cells ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 255 ◽  
Author(s):  
Miruna Mihaela Micheu ◽  
Alina Ioana Scarlatescu ◽  
Alexandru Scafa-Udriste ◽  
Maria Dorobantu
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Fate ◽  
Cell Biology ◽  
Molecular Mechanisms ◽  
Unmet Need ◽  
Cardiac Regeneration ◽  
Cell Types ◽  
Great Promise ◽  
Omics Data

Despite significant progress in treating ischemic cardiac disease and succeeding heart failure, there is still an unmet need to develop effective therapeutic strategies given the persistent high-mortality rate. Advances in stem cell biology hold great promise for regenerative medicine, particularly for cardiac regeneration. Various cell types have been used both in preclinical and clinical studies to repair the injured heart, either directly or indirectly. Transplanted cells may act in an autocrine and/or paracrine manner to improve the myocyte survival and migration of remote and/or resident stem cells to the site of injury. Still, the molecular mechanisms regulating cardiac protection and repair are poorly understood. Stem cell fate is directed by multifaceted interactions between genetic, epigenetic, transcriptional, and post-transcriptional mechanisms. Decoding stem cells’ “panomic” data would provide a comprehensive picture of the underlying mechanisms, resulting in patient-tailored therapy. This review offers a critical analysis of omics data in relation to stem cell survival and differentiation. Additionally, the emerging role of stem cell-derived exosomes as “cell-free” therapy is debated. Last but not least, we discuss the challenges to retrieve and analyze the huge amount of publicly available omics data.

scholarly journals Extracellular Vesicles: An Emerging Mechanism Governing the Secretion and Biological Roles of Tenascin-C

2021 ◽  
Vol 12 ◽  
Author(s):  
Lucas Albacete-Albacete ◽  
Miguel Sánchez-Álvarez ◽  
Miguel Angel del Pozo
Keyword(s):  
Extracellular Vesicles ◽  
Molecular Mechanisms ◽  
Cell Communication ◽  
Cell Types ◽  
Target Cells ◽  
Tenascin C ◽  
Signalling Molecules ◽  
Inflammatory Processes ◽  
Bona Fide ◽  
Cellular Components

ECM composition and architecture are tightly regulated for tissue homeostasis. Different disorders have been associated to alterations in the levels of proteins such as collagens, fibronectin (FN) or tenascin-C (TnC). TnC emerges as a key regulator of multiple inflammatory processes, both during physiological tissue repair as well as pathological conditions ranging from tumor progression to cardiovascular disease. Importantly, our current understanding as to how TnC and other non-collagen ECM components are secreted has remained elusive. Extracellular vesicles (EVs) are small membrane-bound particles released to the extracellular space by most cell types, playing a key role in cell-cell communication. A broad range of cellular components can be transported by EVs (e.g. nucleic acids, lipids, signalling molecules and proteins). These cargoes can be transferred to target cells, potentially modulating their function. Recently, several extracellular matrix (ECM) proteins have been characterized as bona fide EV cargoes, exosomal secretion being particularly critical for TnC. EV-dependent ECM secretion might underpin diseases where ECM integrity is altered, establishing novel concepts in the field such as ECM nucleation over long distances, and highlighting novel opportunities for diagnostics and therapeutic intervention. Here, we review recent findings and standing questions on the molecular mechanisms governing EV–dependent ECM secretion and its potential relevance for disease, with a focus on TnC.

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