Mucosal Ecological Network of Epithelium and Immune Cells for Gut Homeostasis and Tissue Healing.

The intestinal epithelial barrier includes columnar epithelial, Paneth, goblet, enteroendocrine, and tuft cells as well as other cell populations, all of which contribute properties essential for gastrointestinal homeostasis. The intestinal mucosa is covered by mucin, which contains antimicrobial peptides and secretory IgA and prevents luminal bacteria, fungi, and viruses from stimulating intestinal immune responses. Conversely, the transport of luminal microorganisms-mediated by M, dendritic, and goblet cells-into intestinal tissues facilitates the harmonization of active and quiescent mucosal immune responses. The bacterial population within gut-associated lymphoid tissues creates the intratissue cohabitations for harmonized mucosal immunity. Intermolecular and intercellular communication among epithelial, immune, and mesenchymal cells creates an environment conducive for epithelial regeneration and mucosal healing. This review summarizes the so-called intestinal mucosal ecological network-the complex but vital molecular and cellular interactions of epithelial mesenchymal cells, immune cells, and commensal microbiota that achieve intestinal homeostasis, regeneration, and healing.

Spatiotemporal analysis of human intestinal development at single-cell resolution.

Development of the human intestine is not well understood. Here, we link single-cell RNA sequencing and spatial transcriptomics to characterize intestinal morphogenesis through time. We identify 101 cell states including epithelial and mesenchymal progenitor populations and programs linked to key morphogenetic milestones. We describe principles of crypt-villus axis formation; neural, vascular, mesenchymal morphogenesis, and immune population of the developing gut. We identify the differentiation hierarchies of developing fibroblast and myofibroblast subtypes and describe diverse functions for these including as vascular niche cells. We pinpoint the origins of Peyer's patches and gut-associated lymphoid tissue (GALT) and describe location-specific immune programs. We use our resource to present an unbiased analysis of morphogen gradients that direct sequential waves of cellular differentiation and define cells and locations linked to rare developmental intestinal disorders. We compile a publicly available online resource, spatio-temporal analysis resource of fetal intestinal development (STAR-FINDer), to facilitate further work.

Anatomically and Functionally Distinct Lung Mesenchymal Populations Marked by Lgr5 and Lgr6.

The diversity of mesenchymal cell types in the lung that influence epithelial homeostasis and regeneration is poorly defined. We used genetic lineage tracing, single-cell RNA sequencing, and organoid culture approaches to show that Lgr5 and Lgr6, well-known markers of stem cells in epithelial tissues, are markers of mesenchymal cells in the adult lung. Lgr6+ cells comprise a subpopulation of smooth muscle cells surrounding airway epithelia and promote airway differentiation of epithelial progenitors via Wnt-Fgf10 cooperation. Genetic ablation of Lgr6+ cells impairs airway injury repair in vivo. Distinct Lgr5+ cells are located in alveolar compartments and are sufficient to promote alveolar differentiation of epithelial progenitors through Wnt activation. Modulating Wnt activity altered differentiation outcomes specified by mesenchymal cells. This identification of region- and lineage-specific crosstalk between epithelium and their neighboring mesenchymal partners provides new understanding of how different cell types are maintained in the adult lung.

Adventitial Stromal Cells Define Group 2 Innate Lymphoid Cell Tissue Niches.

Type 2 lymphocytes promote both physiologic tissue remodeling and allergic pathology, yet their physical tissue niches are poorly described. Here, we used quantitative imaging to define the tissue niches of group 2 innate lymphoid cells (ILC2s), which are critical instigators of type 2 immunity. We identified a dominant adventitial niche around lung bronchi and larger vessels in multiple tissues, where ILC2s localized with subsets of dendritic and regulatory T cells. However, ILC2s were most intimately associated with adventitial stromal cells (ASCs), a mesenchymal fibroblast-like subset that expresses interleukin-33 (IL-33) and thymic stromal lymphopoietin (TSLP). In vitro, ASCs produced TSLP that supported ILC2 accumulation and activation. ILC2s and IL-13 drove reciprocal ASC expansion and IL-33 expression. During helminth infection, ASC depletion impaired lung ILC2 and Th2 cell accumulation and function, which are in part dependent on ASC-derived IL-33. These data indicate that adventitial niches are conserved sites where ASCs regulate type 2 lymphocyte expansion and function.

Identification of fibroblast progenitors in the developing mouse thymus.

The thymus stroma constitutes a fundamental microenvironment for T-cell generation. Despite the chief contribution of thymic epithelial cells, recent studies emphasize the regulatory role of mesenchymal cells in thymic function. Mesenchymal progenitors are suggested to exist in the postnatal thymus; nonetheless, an understanding of their nature and the mechanism controlling their homeostasis in vivo remains elusive. We resolved two new thymic fibroblast subsets with distinct developmental features. Whereas CD140αß+GP38+SCA-1- cells prevailed in the embryonic thymus and declined thereafter, CD140αß+GP38+SCA-1+ cells emerged in the late embryonic period and predominated in postnatal life. The fibroblastic-associated transcriptional programme was upregulated in CD140αß+GP38+SCA-1+ cells, suggesting that they represent a mature subset. Lineage analysis showed that CD140αß+GP38+SCA-1+ maintained their phenotype in thymic organoids. Strikingly, CD140αß+GP38+SCA-1- generated CD140αß+GP38+SCA-1+, inferring that this subset harboured progenitor cell activity. Moreover, the abundance of CD140αß+GP38+SCA-1+ fibroblasts was gradually reduced in Rag2-/- and Rag2-/-Il2rg-/- thymi, indicating that fibroblast maturation depends on thymic crosstalk. Our findings identify CD140αß+GP38+SCA-1- as a source of fibroblast progenitors and define SCA-1 as a marker for developmental stages of thymic fibroblast differentiation.

Three-axis classification of mouse lung mesenchymal cells reveals two populations of myofibroblasts.

The mesenchyme consists of heterogeneous cell populations that support neighboring structures and are integral to intercellular signaling, but are poorly defined morphologically and molecularly. Leveraging single-cell RNA-sequencing, 3D imaging and lineage tracing, we classify the mouse lung mesenchyme into three proximal-distal axes that are associated with the endothelium, epithelium and interstitium, respectively. From proximal to distal: the vascular axis includes vascular smooth muscle cells and pericytes that transition as arterioles and venules ramify into capillaries; the epithelial axis includes airway smooth muscle cells and two populations of myofibroblasts - ductal myofibroblasts, surrounding alveolar ducts and marked by CDH4, HHIP and LGR6, which persist post-alveologenesis, and alveolar myofibroblasts, surrounding alveoli and marked by high expression of PDGFRA, which undergo developmental apoptosis; and the interstitial axis, residing between the epithelial and vascular trees and sharing the marker MEOX2, includes fibroblasts in the bronchovascular bundle and the alveolar interstitium, which are marked by IL33/DNER/PI16 and Wnt2, respectively. Single-cell imaging reveals a distinct morphology of mesenchymal cell populations. This classification provides a conceptual and experimental framework applicable to other organs.

Terminal differentiation of villus tip enterocytes is governed by distinct Tgfß superfamily members.

The protective and absorptive functions of the intestinal epithelium rely on differentiated enterocytes in the villi. The differentiation of enterocytes is orchestrated by sub-epithelial mesenchymal cells producing distinct ligands along the villus axis, in particular Bmps and Tgfß. Here, we show that individual Bmp ligands and Tgfß drive distinct enterocytic programs specific to villus zonation. Bmp4 is expressed from the centre to the upper part of the villus and activates preferentially genes connected to lipid uptake and metabolism. In contrast, Bmp2 is produced by villus tip mesenchymal cells and it influences the adhesive properties of villus tip epithelial cells and the expression of immunomodulators. Additionally, Tgfß induces epithelial gene expression programs similar to those triggered by Bmp2. Bmp2-driven villus tip program is activated by a canonical Bmp receptor type I/Smad-dependent mechanism. Finally, we establish an organoid cultivation system that enriches villus tip enterocytes and thereby better mimics the cellular composition of the intestinal epithelium. Our data suggest that not only a Bmp gradient but also the activity of individual Bmp drives specific enterocytic programs.

Regulation of murine B lymphopoiesis by stromal cells.

B lymphocytes are crucial for the body's humoral immune response, secreting antibodies generated against foreign antigens to fight infection. Adult murine B lymphopoiesis is initiated in the bone marrow and additional maturation occurs in the spleen. In both these organs, B lymphopoiesis involves interactions with numerous different non-hematopoietic cells, also known as stromal or microenvironment cells, which provide migratory, maturation, and survival signals. A variety of conditional knockout and transgenic mouse models have been used to identify the roles of distinct microenvironment cell types in the regulation of B lymphopoiesis. These studies have revealed that mesenchymal lineage cells and endothelial cells comprise the non-hematopoietic microenvironment cell types that support B lymphopoiesis in the bone marrow. In the spleen, various types of stromal cells and endothelial cells contribute to B lymphocyte maturation. More recently, comprehensive single cell RNA-seq studies have also been used to identify clusters of stromal cell types in the bone marrow and spleen, which will aid in further identifying key regulators of B lymphopoiesis. Here, we review the different types of microenvironment cells and key extrinsic regulators that are known to be involved in the regulation of murine B lymphopoiesis in the bone marrow and spleen.

Origin and diversification of fibroblasts from the sclerotome in zebrafish.

Fibroblasts play an important role in maintaining tissue integrity by secreting components of the extracellular matrix and initiating response to injury. Although the function of fibroblasts has been extensively studied in adults, the embryonic origin and diversification of different fibroblast subtypes during development remain largely unexplored. Using zebrafish as a model, we show that the sclerotome, a sub-compartment of the somite, is the embryonic source of multiple fibroblast subtypes including tenocytes (tendon fibroblasts), blood vessel associated fibroblasts, fin mesenchymal cells, and interstitial fibroblasts. High-resolution imaging shows that different fibroblast subtypes occupy unique anatomical locations with distinct morphologies. Long-term Cre-mediated lineage tracing reveals that the sclerotome also contributes to cells closely associated with the axial skeleton. Ablation of sclerotome progenitors results in extensive skeletal defects. Using photoconversion-based cell lineage analysis, we find that sclerotome progenitors at different dorsal-ventral and anterior-posterior positions display distinct differentiation potentials. Single-cell clonal analysis combined with in vivo imaging suggests that the sclerotome mostly contains unipotent and bipotent progenitors prior to cell migration, and the fate of their daughter cells is biased by their migration paths and relative positions. Together, our work demonstrates that the sclerotome is the embryonic source of trunk fibroblasts as well as the axial skeleton, and local signals likely contribute to the diversification of distinct fibroblast subtypes.

Genetic deficiency of the transcription factor NFAT1 confers protection against fibrogenic responses independent of immune influx.

Idiopathic pulmonary fibrosis (IPF) is marked by unremitting matrix deposition and architectural distortion. Multiple profibrotic pathways contribute to the persistent activation of mesenchymal cells (MCs) in fibrosis, highlighting the need to identify and target common signaling pathways. The transcription factor nuclear factor of activated T cells 1 (NFAT1) lies downstream of second messenger calcium signaling and has been recently shown to regulate key profibrotic mediator autotaxin (ATX) in lung MCs. Herein, we investigate the role of NFAT1 in regulating fibroproliferative responses during the development of lung fibrosis. Nfat1-/--deficient mice subjected to bleomycin injury demonstrated improved survival and protection from lung fibrosis and collagen deposition as compared with bleomycin-injured wild-type (WT) mice. Chimera mice, generated by reconstituting bone marrow cells from WT or Nfat1-/- mice into irradiated WT mice (WT→WT and Nfat1-/-→WT), demonstrated no difference in bleomycin-induced fibrosis, suggesting immune influx-independent fibroprotection in Nfat1-/- mice. Examination of lung tissue and flow sorted lineageneg/platelet-derived growth factor receptor alpha (PDGFRα)pos MCs demonstrated decreased MC numbers, proliferation [↓ cyclin D1 and 5-ethynyl-2'-deoxyuridine (EdU) incorporation], myofibroblast differentiation [↓ α-smooth muscle actin (α-SMA)], and survival (↓ Birc5) in Nfat1-/- mice. Nfat1 deficiency abrogated ATX expression in response to bleomycin in vivo and MCs derived from Nfat1-/- mice demonstrated decreased ATX expression and migration in vitro. Human IPF MCs demonstrated constitutive NFAT1 activation, and regulation of ATX in these cells by NFAT1 was confirmed using pharmacological and genetic inhibition. Our findings identify NFAT1 as a critical mediator of profibrotic processes, contributing to dysregulated lung remodeling and suggest its targeting in MCs as a potential therapeutic strategy in IPF.NEW & NOTEWORTHY Idiopathic pulmonary fibrosis (IPF) is a fatal disease with hallmarks of fibroblastic foci and exuberant matrix deposition, unknown etiology, and ineffective therapies. Several profibrotic/proinflammatory pathways are implicated in accelerating tissue remodeling toward a honeycombed end-stage disease. NFAT1 is a transcriptional factor activated in IPF tissues. Nfat1-deficient mice subjected to chronic injury are protected against fibrosis independent of immune influxes, with suppression of profibrotic mesenchymal phenotypes including proliferation, differentiation, resistance to apoptosis, and autotaxin-related migration.

Lhx6 deficiency causes human embryonic palatal mesenchymal cell mitophagy dysfunction in cleft palate.

BACKGROUND: Overconsumption of retinoic acid (RA) or its analogues/derivatives has been linked to severe craniomaxillofacial malformations, such as cleft palate and midface hypoplasia. It has been noted that RA disturbed the proliferation and migration of embryonic palatal mesenchymal (EPM) cells in these malformations, yet the exact mechanisms underlying these disruptions remained unclear. METHODS: A model of retinoic acid (RA)-induced cleft palate in fetal mice was successfully established. Histological alterations in the palate were evaluated using Hematoxylin and Eosin (H&E) staining and RNA in situ hybridization (RNAscope). Cellular proliferation levels were quantified via the Cell Counting Kit-8 (CCK-8) assay and EdU incorporation assay, while cell migration capabilities were investigated using wound healing and Transwell assays. Mitochondrial functions were assessed through Mito-Tracker fluorescence, mitochondrial reactive oxygen species (ROS) measurement, ATP level quantification, and mitochondrial DNA (mtDNA) copy number analysis. Differential gene expression and associated signaling pathways were identified through bioinformatics analysis. Alterations in the transcriptional and translational levels of Lhx6 and genes associated with mitophagy were quantified using quantitative PCR (qPCR) and Western blot analysis, respectively. Mitochondrial morphology and the mitochondrial autophagosomes within cells were examined through transmission electron microscopy (TEM). RESULTS: Abnormal palatal development in mice, along with impaired proliferation and migration of human embryonic palatal mesenchymal (HEPM) cells, was associated with RA affecting mitochondrial function and concomitant downregulation of Lhx6. Knockdown of Lhx6 in HEPM cells resulted in altered cell proliferation, migration, and mitochondrial function. Conversely, the aberrant mitochondrial function, proliferation, and migration observed in RA-induced HEPM cells were ameliorated by overexpression of Lhx6. Subsequent research demonstrated that Lhx6 ameliorated RA-induced dysfunction in HEPM cells by modulating PINK1/Parkin-mediated mitophagy, thereby activating the MAPK signaling pathways. CONCLUSION: Lhx6 is essential for mitochondrial homeostasis via tuning PINK1/Parkin-mediated mitophagy and MAPK signaling pathways. Downregulation of Lhx6 by RA transcriptionally disturbs the mitochondrial homeostasis, which in turn leads to the proliferation and migration defect in HEPM cells, ultimately causing the cleft palate.

Adipose-derived stromal vascular fraction cells to treat long-term pulmonary sequelae of coronavirus disease 2019: 12-month follow-up.

BACKGROUND AIMS: Long coronavirus disease (COVID) is estimated to occur in up to 20% of patients with coronavirus disease 2019 (COVID-19) infections, with many having persistent pulmonary symptoms. Mesenchymal stromal cells (MSCs) have been shown to have powerful immunomodulatory and anti-fibrotic properties. Autologous adipose-derived (AD) stromal vascular fraction (SVF) contains MSC and other healing cell components and can be obtained by small-volume lipoaspiration and administered on the same day. This study was designed to study the safety of AD SVF infused intravenously to treat the pulmonary symptoms of long COVID. METHODS: Five subjects with persistent cough and dyspnea after hospitalization and subsequent discharge for COVID-19 pneumonia were treated with 40 million intravenous autologous AD SVF cells and followed for 12 months, to include with pulmonary function tests and computed tomography scans of the lung. RESULTS: SVF infusion was safe, with no significant adverse events related to the infusion out to 12 months. Four subjects had improvements in pulmonary symptoms, pulmonary function tests, and computed tomography scans, with some improvement noted as soon as 1 month after SVF treatment. CONCLUSIONS: It is not possible to distinguish between naturally occurring improvement or improvement caused by SVF treatment in this small, uncontrolled study. However, the results support further study of autologous AD SVF as a treatment for long COVID.

Molecular Pathways and Animal Models of Tricuspid Atresia and Univentricular Heart.

The process of valve formation is a complex process that involves intricate interplay between various pathways at precise times. Although we have not completely elucidated the molecular pathways that lead to normal valve formation, we have identified a few major players in this process. We are now able to implicate TGF-ß, BMP, and NOTCH as suspects in tricuspid atresia (TA), as well as their downstream targets: NKX2-5, TBX5, NFATC1, GATA4, and SOX9. We know that the TGF-ß and the BMP pathways converge on the SMAD4 molecule, and we believe that this molecule plays a very important role to tie both pathways to TA. Similarly, we look at the NOTCH pathway and identify the HEY2 as a potential link between this pathway and TA. Another transcription factor that has been implicated in TA is NFATC1. While several mouse models exist that include part of the TA abnormality as their phenotype, no true mouse model can be said to represent TA. Bridging this gap will surely shed light on this complex molecular pathway and allow for better understanding of the disease process.

Osteogenic microenvironment affects palatal development through glycolysis.

Palate development involves various events, including proliferation, osteogenic differentiation, and epithelial-mesenchymal transition. Disruption of these processes can result in the cleft palate (CP). Mouse embryonic palatal mesenchyme (MEPM) cells are commonly used to explore the mechanism of palatal development and CP. However, the role of the microenvironment in the biological properties of MEPM cells, which undergoes dynamic changes during palate development, is rarely reported. In this study, we investigated whether there were differences between the palatal shelf mesenchyme at different developmental stages. Our results found that the palatal shelves facilitate proliferation at the early palate stage at mouse embryonic day (E) 13.5 and the tendency towards osteogenesis at E15.5, the late palate development stage. And the osteogenic microenvironment, which was mimicked by osteogenic differentiation medium (OIM), affected the biological properties of MEPM cells when compared to the routine medium. Specifically, MEPM cells showed slower proliferation, shorter S phase, increased apoptosis, and less migration distance after osteogenesis. E15.5 MEPM cells were more sensitive than E13.5, showing an earlier change. Moreover, E13.5 MEPM cells had weaker osteogenic ability than E15.5, and both MEPM cells exhibited different Lactate dehydrogenase A (LDHA) and Cytochrome c (CytC) expressions in OIM compared to routine medium, suggesting that glycolysis might be associated with the influence of the osteogenic microenvironment on MEPM cells. By comparing the stemness of the two cells, we investigated that the stemness of E13.5 MEPM cells was stronger than that of E15.5 MEPM cells, and E15.5 MEPM cells were more like differentiated cells than stem cells, as their capacity to differentiate into multiple cell fates was reduced. E13.5 MEPM cells might be the precursor cells of E15.5 MEPM cells. Our results enriched the understanding of the effect of the microenvironment on the biological properties of E13.5 and E15.5 MEPM cells, which should be considered when using MEPM cells as a model for palatal studies in the future.

p62/SQSTM1 indirectly mediates remote multipotent mesenchymal cells and rescues bone loss and bone marrow integrity in ovariectomized rats.

Intramuscular administration of p62/SQSTM1 (sequestosome1)-encoding plasmid demonstrated an anticancer effect in rodent models and dogs as well as a high safety profile and the first evidence of clinical benefits in humans. Also, an anti-inflammatory effect of the plasmid was reported in several rodent disease models. Yet, the mechanisms of action for the p62 plasmid remain unknown. Here, we tested a hypothesis that the p62-plasmid can act through the modulation of bone marrow multipotent mesenchymal cells (MSCs). We demonstrated that a p62 plasmid can affect MSCs indirectly by stimulating p62-transfected cells to secrete an active ingredient(s) sensed by untransfected MSCs. When we transfected MSCs with the p62-plasmid, collected their supernatant, and added it to an untransfected MSCs culture, it switched the differentiation state and prompt osteogenic responses of the untransfected MSCs. According to an accepted viewpoint, ovariectomy leads to bone pathology via dysregulation of MSCs, and restoring the MSC homeostasis would restore ovariectomy-induced bone damage. To validate our in vitro observations in a clinically relevant in vivo model, we administered the p62 plasmid to ovariectomized rats. It partially reversed bone loss and notably reduced adipogenesis with concurrent reestablishing of the MSC subpopulation pool within the bone marrow. Overall, our study suggests that remote modulation of progenitor MSCs via administering a p62-encoding plasmid may constitute a mechanism for its previously reported effects and presents a feasible disease-preventing and/or therapeutic strategy.

GLI1+ cells are a source of repair-supportive mesenchymal cells (RSMCs) during airway epithelial regeneration.

Repair-supportive mesenchymal cells (RSMCs) have been recently reported in the context of naphthalene (NA)-induced airway injury and regeneration. These cells transiently express smooth muscle actin (Acta2) and are enriched with platelet-derived growth factor receptor alpha (Pdgfra) and fibroblast growth factor 10 (Fgf10) expression. Genetic deletion of Ctnnb1 (gene coding for beta catenin) or Fgf10 in these cells using the Acta2-Cre-ERT2 driver line after injury (defined as NA-Tam condition; Tam refers to tamoxifen) led to impaired repair of the airway epithelium. In this study, we demonstrate that RSMCs are mostly captured using the Acta2-Cre-ERT2 driver when labeling occurs after (NA-Tam condition) rather than before injury (Tam-NA condition), and that their expansion occurs mostly between days 3 and 7 following NA treatment. Previous studies have shown that lineage-traced peribronchial GLI1+ cells are transiently amplified after NA injury. Here, we report that Gli1 expression is enriched in RSMCs. Using lineage tracing with Gli1Cre-ERT2 mice combined with genetic inactivation of Fgf10, we show that GLI1+ cells with Fgf10 deletion fail to amplify around the injured airways, thus resulting in impaired airway epithelial repair. Interestingly, Fgf10 expression is not upregulated in GLI1+ cells following NA treatment, suggesting that epithelial repair is mostly due to the increased number of Fgf10-expressing GLI1+ cells. Co-culture of SCGB1A1+ cells with GLI1+ cells isolated from non-injured or injured lungs showed that GLI1+ cells from these two conditions are similarly capable of supporting bronchiolar organoid (or bronchiolosphere) formation. Single-cell RNA sequencing on sorted lineage-labeled cells showed that the RSMC signature resembles that of alveolar fibroblasts. Altogether, our study provides strong evidence for the involvement of mesenchymal progenitors in airway epithelial regeneration and highlights the critical role played by Fgf10-expressing GLI1+ cells in this context.

Senescence-associated secretory phenotypes in mesenchymal cells contribute to cytotoxic immune response in oral lichen planus.

Oral lichen planus is a chronic inflammatory condition that adversely affects the oral mucosa; however, its etiology remains elusive. Consequently, therapeutic interventions for oral lichen planus are limited to symptomatic management. This study provides evidence of the accumulation of senescent mesenchymal cells, CD8 + T cells, and natural killer cells in patients with oral lichen planus. We profiled the patients' tissues using the National Center for Biotechnology Information Gene Expression Omnibus database and found that senescence-related genes were upregulated in these tissues by gene set enrichment analysis. Immunohistochemical analysis showed increased senescent mesenchymal cells in the subepithelial layer of patients with oral lichen planus. Single-cell RNA-seq data retrieved from the Gene Expression Omnibus database of patients with oral lichen planus revealed that mesenchymal cells were marked by the upregulation of senescence-related genes. Cell-cell communication analysis using CellChat showed that senescent mesenchymal cells significantly influenced CD8 + T cells and natural killer cells via CXCL12-CXCR4 signaling, which is known to activate and recruit CD8 + T cells and NK cells. Finally, in vitro assays demonstrated that the secretion of senescence-associated factors from mesenchymal cells stimulated the activation of T cells and natural killer cells and promoted epithelial cell senescence and cytotoxicity. These findings suggest that the accumulation of mesenchymal cells with senescence-associated secretory phenotype may be a key driver of oral lichen planus pathogenesis.

Excess vitamin a might contribute to submucous clefting by inhibiting WNT-mediated bone formation.

OBJECTIVES: Cleft lip and/or palate (CLP) is a common craniofacial birth defect caused by genetic as well as environmental factors. The phenotypic spectrum of CLP also includes submucous clefts with a defect in the palatal bone. To elucidate the contribution of vitamin A, we evaluated the effects of the vitamin A metabolite all-trans retinoic acid (ATRA) on the osteogenic differentiation and mineralization of mouse embryonic palatal mesenchymal cells (MEPM). SETTING AND SAMPLE POPULATION: MEPM cells were isolated from the prefusion palates of E13 mouse embryos from three different litters. MATERIALS AND METHODS: MEPM cells were cultured with and without 0.5 µM ATRA in osteogenic medium. Differentiation was analysed by the expression of osteogenic marker genes and alkaline phosphatase (ALP) activity after 1, 2, and 7 days. The expression of Wnt marker genes was also analysed. Mineralization was assessed by alizarin red staining after 7, 14, 21, and 28 days. RESULTS: The bone marker genes Sp7, Runx2, Alpl, and Col1a1 were inhibited 10% ± 2%, 59% ± 7%, 79% ± 12% and 57% ± 20% (P < .05) at day 7. ALP activity was inhibited at days 1 and 7 by 35 ± 0% (P < .05) and 23 ± 6% (P < .001). ATRA also inhibited mineralization at 3 and 4 weeks. Finally, expression of the universal Wnt marker gene Axin2 was strongly reduced, by 31 ± 18% (P < .001), at day 7. CONCLUSION: Our data indicate that ATRA (vitamin A) inhibits bone formation by reducing Wnt signalling. This might contribute to the molecular aetiology of submucous clefting.

Cultured Mesenchymal Cells from Nasal Turbinate as a Cellular Model of the Neurodevelopmental Component of Schizophrenia Etiology.

The study of neurodevelopmental molecular mechanisms in schizophrenia requires the development of adequate biological models such as patient-derived cells and their derivatives. We previously utilized cell lines with neural progenitor properties (CNON) derived from the superior or middle turbinates of patients with schizophrenia and control groups to study schizophrenia-specific gene expression. In this study, we analyzed single-cell RNA seq data from two CNON cell lines (one derived from an individual with schizophrenia (SCZ) and the other from a control group) and two biopsy samples from the middle turbinate (MT) (also from an individual with SCZ and a control). We compared our data with previously published data regarding the olfactory neuroepithelium and demonstrated that CNON originated from a single cell type present both in middle turbinate and the olfactory neuroepithelium and expressed in multiple markers of mesenchymal cells. To define the relatedness of CNON to the developing human brain, we also compared CNON datasets with scRNA-seq data derived from an embryonic brain and found that the expression profile of the CNON closely matched the expression profile one of the cell types in the embryonic brain. Finally, we evaluated the differences between SCZ and control samples to assess the utility and potential benefits of using CNON single-cell RNA seq to study the etiology of schizophrenia.

Magnetic Nanoemulsions for the Intra-Articular Delivery of Ascorbic Acid and Dexamethasone.

(1) Osteoarthritis (OA) is a progressive joint degenerative disease that currently has no cure. Limitations in the development of innovative disease modifying therapies are related to the complexity of the underlying pathogenic mechanisms. In addition, there is the unmet need for efficient drug delivery methods. Magnetic nanoparticles (MNPs) have been proposed as an efficient modality for the delivery of bioactive molecules within OA joints, limiting the side effects associated with systemic delivery. We previously demonstrated MNP's role in increasing cell proliferation and chondrogenesis. In the design of intra-articular therapies for OA, the combined NE-MNP delivery system could provide increased stability and biological effect. (2) Proprietary Fe3O4 MNPs formulated as oil-in-water (O/W) magneto nanoemulsions (MNEs) containing ascorbic acid and dexamethasone were tested for size, stability, magnetic properties, and in vitro biocompatibility with human primary adipose mesenchymal cells (ADSC), cell mobility, and chondrogenesis. In vivo biocompatibility was tested after systemic administration in mice. (3) We report high MNE colloidal stability, magnetic properties, and excellent in vitro and in vivo biocompatibility. By increasing ADSC migration potential and chondrogenesis, MNE carrying dexamethasone and ascorbic acid could reduce OA symptoms while protecting the cartilage layer.