Project description:The transition zones (TZs) of the squamous and columnar epithelium constitute hotspots for the emergence of cancers, often preceded by metaplasia, where one epithelial type is replaced by cells of another type. Yet, it remains uncertain how the spatial organization of the epithelia is maintained and how the TZ niche is remodeled during metaplasia. Here, we used single-cell RNA-sequencing to characterize subpopulations of the epithelium as well as the underlying stromal compartment of endo and ectocervix, encompassing the TZ. Mouse lineage tracing, organoid culture and smRNA-ISH revealed that the two epithelia derive from two separate cervix-resident lineage-specific stem cell populations that are regulated by opposing WNT signals from the stroma. Using a mouse model of cervical metaplasia, we further show that the endocervical stroma undergoes remodeling and increased expression of WNT signaling inhibitor Dickkopf-2 (DKK2), promoting the outgrowth of ectocervical stem cells. Thus, homeostasis at the TZ results from divergent stromal signals, driving the differential proliferation of resident epithelial lineages.
Project description:The transition zones of the squamous and columnar epithelia constitute hotspots for the emergence of cancer, often preceded by metaplasia, in which one epithelial type is replaced by another. It remains unclear how the epithelial spatial organization is maintained and how the transition zone niche is remodelled during metaplasia. Here we used single-cell RNA sequencing to characterize epithelial subpopulations and the underlying stromal compartment of endo- and ectocervix, encompassing the transition zone. Mouse lineage tracing, organoid culture and single-molecule RNA in situ hybridizations revealed that the two epithelia derive from separate cervix-resident lineage-specific stem cell populations regulated by opposing Wnt signals from the stroma. Using a mouse model of cervical metaplasia, we further show that the endocervical stroma undergoes remodelling and increases expression of the Wnt inhibitor Dickkopf-2 (DKK2), promoting the outgrowth of ectocervical stem cells. Our data indicate that homeostasis at the transition zone results from divergent stromal signals, driving the differential proliferation of resident epithelial lineages.
Project description:The cellular origin of cervical cancers remains unclear. Revealing molecular details of transformation in this tissue has been hampered by the lack of culture systems, resembling the in vivo cervical architecture. Here we established a long-term in vitro 3D cervical organoid model derived from stem cells of human or mouse cervical tissue which recapitulates the in vivo stratified ectocervical and columnar endocervical epithelium. Stratified and columnar cervical epithelia arise from two discrete unipotent stem cell populations of the endocervix. Unique stem cell signatures reveal a dependency on intrinsic Notch and Wnt microenvironmental signals. The genetic signatures of KRT5+ stratified vs KRT7+ columnar cervical cells establish discrete groups of cervical cancer of the squamous and adenocarcinoma types, respectively. Cervical tissue morphology is guided by the interplay of two discrete unipotent cervical stem cell populations and the spatio-temporal distribution of signals from the stroma.
Project description:The cellular origin of cervical cancers remains unclear. Revealing molecular details of transformation in this tissue has been hampered by the lack of culture systems, resembling the in vivo cervical architecture. Here we established a long-term in vitro 3D cervical organoid model derived from stem cells of human or mouse cervical tissue which recapitulates the in vivo stratified ectocervical and columnar endocervical epithelium. Stratified and columnar cervical epithelia arise from two discrete unipotent stem cell populations of the endocervix. Unique stem cell signatures reveal a dependency on intrinsic Notch and Wnt microenvironmental signals. The genetic signatures of KRT5+ stratified vs KRT7+ columnar cervical cells establish discrete groups of cervical cancer of the squamous and adenocarcinoma types, respectively. Cervical tissue morphology is guided by the interplay of two discrete unipotent cervical stem cell populations and the spatio-temporal distribution of signals from the stroma.
Project description:Most vertebrate species undergo tooth replacement throughout adult life. This process is marked by the shedding of existing teeth and the regeneration of tooth organs. However, little is known about the genetic circuitry regulating tooth replacement. Here, we tested whether fish orthologs of genes known to regulate mammalian hair regeneration have effects on tooth replacement. Using two fish species that demonstrate distinct modes of tooth regeneration, threespine stickleback (Gasterosteus aculeatus) and zebrafish (Danio rerio), we found that transgenic overexpression of four different genes changed tooth replacement rates in the direction predicted by a hair regeneration model: Wnt10a and Grem2a increased tooth replacement rate, whereas Bmp6 and Dkk2 strongly inhibited tooth formation. Thus, similar to known roles in hair regeneration, Wnt and BMP signals promote and inhibit regeneration, respectively. Regulation of total tooth number was separable from regulation of replacement rates. RNA sequencing of stickleback dental tissue showed that Bmp6 overexpression resulted in an upregulation of Wnt inhibitors. Together, these data support a model in which different epithelial organs, such as teeth and hair, share genetic circuitry driving organ regeneration.
Project description:Goblet cell metaplasia and mucus hypersecretion are disabling hallmarks of chronic lung diseases for which no curative treatments are available. Therapies targeting specific upstream drivers of asthma have had variable results. We hypothesized that an a priori-knowledge independent approach would point to new therapies for airway goblet cell metaplasia. We analyzed the transcriptome of an organotypic model of human goblet cell metaplasia. We combined our data with previously published datasets from IL13-exposed in vitro and asthmatic in vivo human airway epithelial cells. The drug perturbation-response connectivity approach identified the heat shock protein 90 (HSP90) inhibitor geldanamycin as a candidate for reverting airway goblet cell metaplasia. We found that geldanamycin not only prevented but reverted IL13-induced goblet cell metaplasia. Geldanamycin did not induce goblet cell death, did not solely block mucin synthesis, and did not block IL13 receptor-proximal signaling. Moreover, the transcriptional effects of geldanamycin were absent in unstimulated cells and became evident only after stimulation with IL13. The predicted mechanism of action suggested that geldanamycin should also revert IL17-induced goblet cell metaplasia, a prediction confirmed by our data. Our findings suggest HSP90 activity may be required for persistence of goblet cell metaplasia driven by various mechanisms in chronic lung diseases.
Project description:Barrett's esophagus is characterized by the replacement of squamous epithelium with specialized intestinal metaplastic mucosa. The exact mechanisms of initiation and development of Barrett's metaplasia remain unknown, but a hypothesis of successful adaptation against noxious reflux components has been proposed. To search for the repertoire of adaptation mechanisms of Barrett's metaplasia, we employed high-throughput functional genomic and proteomic methods that defined the molecular background of metaplastic mucosa resistance to reflux. Transcriptional profiling was established for 23 pairs of esophageal squamous epithelium and Barrett's metaplasia tissue samples using Affymetrix U133A 2.0 GeneChips and validated by quantitative real-time polymerase chain reaction. Differences in protein composition were assessed by electrophoretic and mass-spectrometry-based methods. Among 2,822 genes differentially expressed between Barrett's metaplasia and squamous epithelium, we observed significantly overexpressed metaplastic mucosa genes that encode cytokines and growth factors, constituents of extracellular matrix, basement membrane and tight junctions, and proteins involved in prostaglandin and phosphoinositol metabolism, nitric oxide production, and bioenergetics. Their expression likely reflects defense and repair responses of metaplastic mucosa, whereas overexpression of genes encoding heat shock proteins and several protein kinases in squamous epithelium may reflect lower resistance of normal esophageal epithelium than Barrett's metaplasia to reflux components. Despite the methodological and interpretative difficulties in data analyses discussed in this paper, our studies confirm that Barrett's metaplasia may be regarded as a specific microevolution allowing for accumulation of mucosal morphological and physiological changes that better protect against reflux injury. Department of Gastroenterology, Medical Center for Postgraduate Education and Maria SkM-EM-^Bodowska-Curie Memorial Cancer Center and Institute of Oncology, 02-781 Warsaw, Poland 2 types of tissue sample derived from the same patient: > Normal squamous epithelium (NE) from patients with longsegment of BarretM-bM-^@M-^Ys epithelium > Metaplastic epithelium from BarrettM-bM-^@M-^Ys esophagus (BE)