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American Journal of Respiratory and... Dec 2020Declining lung function in patients with interstitial lung disease is accompanied by epithelial remodeling and progressive scarring of the gas-exchange region. There is...
Declining lung function in patients with interstitial lung disease is accompanied by epithelial remodeling and progressive scarring of the gas-exchange region. There is a need to better understand the contribution of basal cell hyperplasia and associated mucosecretory dysfunction to the development of idiopathic pulmonary fibrosis (IPF). We sought to decipher the transcriptome of freshly isolated epithelial cells from normal and IPF lungs to discern disease-dependent changes within basal stem cells. Single-cell RNA sequencing was used to map epithelial cell types of the normal and IPF human airways. Organoid and air-liquid interface cultures were used to investigate functional properties of basal cell subtypes. We found that basal cells included multipotent and secretory primed subsets in control adult lung tissue. Secretory primed basal cells include an overlapping molecular signature with basal cells obtained from the distal lung tissue of IPF lungs. We confirmed that NOTCH2 maintains undifferentiated basal cells and restricts basal-to-ciliated differentiation, and we present evidence that NOTCH3 functions to restrain secretory differentiation. Basal cells are dynamically regulated in disease and are specifically biased toward the expansion of the secretory primed basal cell subset in IPF. Modulation of basal cell plasticity may represent a relevant target for therapeutic intervention in IPF.
Topics: Aged; Alveolar Epithelial Cells; Basement Membrane; Case-Control Studies; Cell Plasticity; Cell Proliferation; Cell Self Renewal; Epithelial Cells; Female; Gene Expression Profiling; Humans; Idiopathic Pulmonary Fibrosis; Male; Middle Aged; RNA-Seq; Respiratory Mucosa; Single-Cell Analysis; Transcriptome; Young Adult
PubMed: 32692579
DOI: 10.1164/rccm.201904-0792OC -
Cell Stem Cell Jan 2021The derivation of tissue-specific stem cells from human induced pluripotent stem cells (iPSCs) would have broad reaching implications for regenerative medicine. Here, we...
The derivation of tissue-specific stem cells from human induced pluripotent stem cells (iPSCs) would have broad reaching implications for regenerative medicine. Here, we report the directed differentiation of human iPSCs into airway basal cells ("iBCs"), a population resembling the stem cell of the airway epithelium. Using a dual fluorescent reporter system (NKX2-1;TP63), we track and purify these cells as they first emerge as developmentally immature NKX2-1 lung progenitors and subsequently augment a TP63 program during proximal airway epithelial patterning. In response to primary basal cell medium, NKX2-1/TP63 cells display the molecular and functional phenotype of airway basal cells, including the capacity to self-renew or undergo multi-lineage differentiation in vitro and in tracheal xenografts in vivo. iBCs and their differentiated progeny model perturbations that characterize acquired and genetic airway diseases, including the mucus metaplasia of asthma, chloride channel dysfunction of cystic fibrosis, and ciliary defects of primary ciliary dyskinesia.
Topics: Cell Differentiation; Epithelial Cells; Humans; Induced Pluripotent Stem Cells; Lung; Pluripotent Stem Cells; Trachea
PubMed: 33098807
DOI: 10.1016/j.stem.2020.09.017 -
Cellular & Molecular Immunology Jun 2023Osteoarthritis (OA) is a degenerative multifactorial disease with concomitant structural, inflammatory, and metabolic changes that fluctuate in a temporal and... (Review)
Review
Osteoarthritis (OA) is a degenerative multifactorial disease with concomitant structural, inflammatory, and metabolic changes that fluctuate in a temporal and patient-specific manner. This complexity has contributed to refractory responses to various treatments. MSCs have shown promise as multimodal therapeutics in mitigating OA symptoms and disease progression. Here, we evaluated 15 randomized controlled clinical trials (RCTs) and 11 nonrandomized RCTs using culture-expanded MSCs in the treatment of knee OA, and we found net positive effects of MSCs on mitigating pain and symptoms (improving function in 12/15 RCTs relative to baseline and in 11/15 RCTs relative to control groups at study endpoints) and on cartilage protection and/or repair (18/21 clinical studies). We examined MSC dose, tissue of origin, and autologous vs. allogeneic origins as well as patient clinical phenotype, endotype, age, sex and level of OA severity as key parameters in parsing MSC clinical effectiveness. The relatively small sample size of 610 patients limited the drawing of definitive conclusions. Nonetheless, we noted trends toward moderate to higher doses of MSCs in select OA patient clinical phenotypes mitigating pain and leading to structural improvements or cartilage preservation. Evidence from preclinical studies is supportive of MSC anti-inflammatory and immunomodulatory effects, but additional investigations on immunomodulatory, chondroprotective and other clinical mechanisms of action are needed. We hypothesize that MSC basal immunomodulatory "fitness" correlates with OA treatment efficacy, but this hypothesis needs to be validated in future studies. We conclude with a roadmap articulating the need to match an OA patient subset defined by molecular endotype and clinical phenotype with basally immunomodulatory "fit" or engineered-to-be-fit-for-OA MSCs in well-designed, data-intensive clinical trials to advance the field.
Topics: Humans; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; Osteoarthritis, Knee; Pain; Treatment Outcome; Randomized Controlled Trials as Topic; Non-Randomized Controlled Trials as Topic
PubMed: 37095295
DOI: 10.1038/s41423-023-01020-1 -
Proceedings of the National Academy of... Dec 2013Here, using further optimized 3D culture that allows highly selective induction and long-term growth of human ES cell (hESC)-derived cortical neuroepithelium, we...
Here, using further optimized 3D culture that allows highly selective induction and long-term growth of human ES cell (hESC)-derived cortical neuroepithelium, we demonstrate unique aspects of self-organization in human neocorticogenesis. Self-organized cortical tissue spontaneously forms a polarity along the dorsocaudal-ventrorostral axis and undergoes region-specific rolling morphogenesis that generates a semispherical structure. The neuroepithelium self-forms a multilayered structure including three neuronal zones (subplate, cortical plate, and Cajal-Retzius cell zones) and three progenitor zones (ventricular, subventricular, and intermediate zones) in the same apical-basal order as seen in the human fetal cortex in the early second trimester. In the cortical plate, late-born neurons tend to localize more basally to early-born neurons, consistent with the inside-out pattern seen in vivo. Furthermore, the outer subventricular zone contains basal progenitors that share characteristics with outer radial glia abundantly found in the human, but not mouse, fetal brain. Thus, human neocorticogenesis involves intrinsic programs that enable the emergence of complex neocortical features.
Topics: Amides; Cell Culture Techniques; Cell Polarity; Collagen; Drug Combinations; Embryonic Stem Cells; Humans; Laminin; Neocortex; Neuroglia; Organogenesis; Proteoglycans; Pyridines; Species Specificity
PubMed: 24277810
DOI: 10.1073/pnas.1315710110 -
Developmental Biology Sep 2022Neurons and epithelia are viewed as fundamentally different cell types, yet some sensory neurons exhibit hallmarks of epithelial cells. For example, they use tight... (Review)
Review
Neurons and epithelia are viewed as fundamentally different cell types, yet some sensory neurons exhibit hallmarks of epithelial cells. For example, they use tight junctions to form a diffusion barrier continuous with the skin or other epithelia and they exhibit bona fide apical-basal polarity, with an outward-facing apical surface that is biochemically and functionally distinct from their inward-facing basolateral surface. Yet they are unmistakeably neurons with axon-dendrite polarity. Examples include olfactory receptor neurons and photoreceptors. In this review, I highlight how viewing these neurons as specialized epithelial cells informs our understanding of their development and raises intriguing questions about the establishment of apical-basal and axon-dendrite polarity.
Topics: Cell Polarity; Epithelial Cells; Epithelium; Neurons; Tight Junctions
PubMed: 35772473
DOI: 10.1016/j.ydbio.2022.06.012 -
Cell Stem Cell Nov 2008Here, we demonstrate self-organized formation of apico-basally polarized cortical tissues from ESCs using an efficient three-dimensional aggregation culture (SFEBq...
Here, we demonstrate self-organized formation of apico-basally polarized cortical tissues from ESCs using an efficient three-dimensional aggregation culture (SFEBq culture). The generated cortical neurons are functional, transplantable, and capable of forming proper long-range connections in vivo and in vitro. The regional identity of the generated pallial tissues can be selectively controlled (into olfactory bulb, rostral and caudal cortices, hem, and choroid plexus) by secreted patterning factors such as Fgf, Wnt, and BMP. In addition, the in vivo-mimicking birth order of distinct cortical neurons permits the selective generation of particular layer-specific neurons by timed induction of cell-cycle exit. Importantly, cortical tissues generated from mouse and human ESCs form a self-organized structure that includes four distinct zones (ventricular, early and late cortical-plate, and Cajal-Retzius cell zones) along the apico-basal direction. Thus, spatial and temporal aspects of early corticogenesis are recapitulated and can be manipulated in this ESC culture.
Topics: Animals; Antigens, Differentiation; Body Patterning; Bone Morphogenetic Protein 4; Cell Cycle; Cell Differentiation; Cerebral Cortex; Embryonic Stem Cells; Fibroblast Growth Factor 8; Gene Expression Regulation, Developmental; Homeostasis; Humans; Immunohistochemistry; Mice; Neurons; Signal Transduction; Tissue Culture Techniques; Wnt Proteins; Wnt3 Protein
PubMed: 18983967
DOI: 10.1016/j.stem.2008.09.002 -
Philosophical Transactions of the Royal... Dec 2016Self-assembly of two important components of the cytoskeleton of eukaryotic cells, actin microfilaments and microtubules (MTs) results in polar filaments of one... (Review)
Review
Self-assembly of two important components of the cytoskeleton of eukaryotic cells, actin microfilaments and microtubules (MTs) results in polar filaments of one chirality. As is true for bacterial flagella, in actin microfilaments, screw direction is important for assembly processes and motility. For MTs, polar orientation within the cell is paramount. The alignment of these elements in the cell cytoplasm gives rise to emergent properties, including the potential for cell differentiation and specialization. Complex MTs with a characteristic chirality are found in basal bodies and centrioles; this chirality is preserved in cilia. In motile cilia, it is reflected in the direction of the effective stroke. The positioning of the basal body or cilia on the cell surface depends on polarity proteins. In evolution, survival depends on global polarity information relayed to the cell in part by orientation of the MT and actin filament cytoskeletons and the chirality of the basal body to determine left and right coordinates within a defined anterior-posterior cell and tissue axis.This article is part of the themed issue 'Provocative questions in left-right asymmetry'.
Topics: Actin Cytoskeleton; Biological Evolution; Cytoskeleton; Eukaryotic Cells; Microtubules
PubMed: 27821520
DOI: 10.1098/rstb.2015.0408 -
American Journal of Physiology. Cell... Dec 2022The epidermis is a specialized epithelium that constitutes the outermost layer of the skin, and it provides a protective barrier against environmental assaults.... (Review)
Review
The epidermis is a specialized epithelium that constitutes the outermost layer of the skin, and it provides a protective barrier against environmental assaults. Primarily consisting of multilayered keratinocytes, the epidermis is continuously renewed by proliferation of stem cells and the differentiation of their progeny, which undergo terminal differentiation as they leave the basal layer and move upward toward the surface, where they die and slough off. Basal keratinocytes rest on a basement membrane at the dermal-epidermal junction that is composed of specific extracellular matrix proteins organized into interactive and mechanically supportive networks. Firm attachment of basal keratinocytes, and their dynamic regulation via focal adhesions and hemidesmosomes, is essential for maintaining major skin processes, such as self-renewal, barrier function, and resistance to physical and chemical stresses. The adhesive integrin receptors expressed by epidermal cells serve structural, signaling, and mechanosensory roles that are critical for epidermal cell anchorage and tissue homeostasis. More specifically, the basement membrane components play key roles in preserving the stem cell pool, and establishing cell polarity cues enabling asymmetric cell divisions, which result in the transition from a proliferative basal cell layer to suprabasal cells committed to terminal differentiation. Finally, through a well-regulated sequence of synthesis and remodeling, the components of the dermal-epidermal junction play an essential role in regeneration of the epidermis during skin healing. Here too, they provide biological and mechanical signals that are essential to the restoration of barrier function.
Topics: Epidermis; Epidermal Cells; Basement Membrane; Keratinocytes; Dermis; Cell Differentiation
PubMed: 36374168
DOI: 10.1152/ajpcell.00069.2022 -
Journal of Cell Science Aug 2014Cell polarity is characterised by differences in structure, composition and function between at least two poles of a cell. In epithelial cells, these spatial differences... (Review)
Review
Cell polarity is characterised by differences in structure, composition and function between at least two poles of a cell. In epithelial cells, these spatial differences allow for the formation of defined apical and basal membranes. It has been increasingly recognised that cell-matrix interactions and integrins play an essential role in creating epithelial cell polarity, although key gaps in our knowledge remain. This Commentary will discuss the mounting evidence for the role of integrins in polarising epithelial cells. We build a model in which both inside-out signals to polarise basement membrane assembly at the basal surface, and outside-in signals to control microtubule apical-basal orientation and vesicular trafficking are required for establishing and maintaining the orientation of epithelial cell polarity. Finally, we discuss the relevance of the basal integrin polarity axis to cancer. This article is part of a Minifocus on Establishing polarity.
Topics: Animals; Basement Membrane; Cell Polarity; Epithelial Cells; Humans; Integrins; Microtubules; Neoplasms
PubMed: 24994933
DOI: 10.1242/jcs.146142