Project description:Primary human epididymis epithelial (HEE) cells are valuable reagents for functional studies on the human epididymis. We used them previously to determine the transcriptional networks that establish cell identity along the length of the epididymis from caput, corpus and cauda. These studies on HEE cells and organoids derived from them revealed important cellular properties. However, similar to other primary cells, HEE cells undergo replicative senescence and de-differentiation in culture. A cocktail of small molecules was shown elsewhere to extend longevity of epithelial basal cells. The components included transforming growth factor β (TGF-β)/bone morphogenetic protein (BMP) antagonists, WNT agonist and Rho-associated and coiled-coil containing protein kinase (ROCK) inhibitor (ROCKi), which together prevented the senescence-related upregulation of TGF-β signaling pathway members. Here we treat HEE cells with the same cocktail and observed enhanced replicative potential and prolonged expression of markers of HEE differentiation. This treatment expands the differentiated HEE cell population available from individual epididymis tissue samples that can be used for molecular, cellular and functional studies.
Project description:Underdeveloped lungs are a primary cause of morbidity and mortality in premature infants, but our ability to help these patients by speeding up lung development are hindered by a lack of understanding of human lung developmental biology. Here, we performed single cell RNA sequencing of the human fetal lung from samples spanning from 11.5 weeks gestation to 21 weeks gestation from the distal lung, middle airways, and the tracheal epithelium. The primary goal of this experiment was to define fetal cell states to serve as a gold standard for pluripotent stem cell-derived lung cells and tissues, and to identify potential signaling pathways that drive differentiation of lung progenitor cells to mature cell types. Additionally, we generated bud tip progenitor organoids from 12 week human fetal lung bud tip progenitors. We show that treatment of bud tip progenitor organoids with a short pulse of dual SMAD activation (BMP4+TGFb1) led to the upregulation of lung basal cell markers, a cell type that serves as a critical stem cell for the adult airway, and that further treatment with dual SMAD inhibition leads to the generation of airway-like organoids containing differentiated cell types of the adult airway, including basal stem cells.
Project description:SUMMARY of the associated publication: Many adult epithelial stem cells cannot undergo prolonged expansion. This may be due to a cell autonomous limitation or a lack of necessary culture conditions. Thus far, the long-term culture of adult stem cells has required the use of Matrigel organoid culture or feeder co-culture systems. We demonstrate that the TGFbetaBMP/SMAD signaling pathway is highly active in the luminal cells of diverse p63+ basal cell-containing epithelia. Indeed, the activation of SMAD signaling in airway stem cells causes their differentiation, while conversely, inhibition of SMAD signaling leads to stem cell hyperplasia and compromised differentiation. Consistently, TGFbetaBMP/SMAD signaling activation prevents mature cell dedifferentiation. Using pharmacologic dual SMAD inhibition, we developed a feeder-free culture system that allows the cloning of single airway basal stem cells and the expansion of airway stem cells from clinical non-invasively obtained samples with high efficiency. Furthermore, the expansion protocols are applicable not only to human cells but also to those of mouse, ferret, and pig. When differentiated epithelia are produced from expanded cells, they exhibit proper epithelial physiology, and respond to clinically relevant pharmacologic agents. Most remarkably, a very wide variety of functional adult epithelial basal stem cells can be expanded despite their differing origins. The goal of this microarray analysis: It has been shown that inhibition of TGFbeta signaling leads to tumorigenesis (e.g. Guasch et al., 2007, and others). It will be important to show whether the dual inhibited population assumes a tumorigenic status in the same or different manner compared to directly isolated progenitor cells. To address this concern, we have done comprehensive transcriptome analysis comparing gene expression signature of airway stem cells at their early and late passages. We do not find tumor-associated gene signatures during stem cell expansion.
Project description:SUBMITTER_CITATION: Dubé E and Cyr DG, The Blood-Epididymis and Human Male Fertility. In: Biology and Regulation of Blood-Tissue Barriers, Cheng CY Editor. 2010, Landes Bioscience. The epididymis can be subdivided into three regions, the caput, corpus and cauda epididymidis, that have different characteristics and functions. Goal was to determine the differential pattern of gene expression along the regions of the human epididymis.
Project description:Gene-specific transcription factors (GSTFs) control of gene transcription by DNA binding and specific protein complex recruitment, which regulates promoter accessibility for transcription initiation by RNA polymerase II. GSTFs that are frequently mutated in colon and rectal carcinomas are Suppressor of Mothers Against Decapentaplegic 2 (SMAD2) and SMAD4, which play an important role in the TGF-β signaling pathways controlling cell fate and proliferation (ref.). The SMAD protein family is a diverse and it can be divided into three subclasses: receptor activated SMADs, inhibitory SMADs and the common SMAD4 co-activator. To study protein interactors of the SMAD protein family we generated a quantitative proteomics pipeline that allows for inducible expression of GFP-tagged SMAD proteins followed by affinity purification and MS analysis. The nuclear importin IPO5 was identified as a novel interacting protein of SMAD1. Overexpression of IPO5 shows forced BMP R-SMAD nuclear localization confirming a functional relationship between BMP but not TGF-β R-SMADs and IPO5. Finally we provide evidence that the length of the lysine stretch in the NLS is involved in importin selection.
Project description:The epididymis can be subdivided into three regions, the caput, corpus and cauda epididymidis, that have different characteristics and functions. Goal was to determine the differential pattern of gene expression along the regions of the human epididymis. Two-condition experiment, region 1 vs region 2. Replicates: 4 biological replicates from each epididymal region.
Project description:Basal cells represent a specific cell type in the epididymis, with specific functions. We performed gene expression analysis to detect differentially regulated genes in basal cells versus other, non-basal, cells in rat epididymis, in order to understand basal cell functions.
Project description:Mammalian spermatozoa acquire their fertilizing ability during epididymal transit. Gene expression patterns along the epididymis are established by specific transcription factor networks that coordinate region-specific functions. The epididymis is usually divided into 3 segments: caput, corpus, and cauda. The human epididymis anatomy does not allow clear distinction between these three segments. To determine to which extent gene expression is segmented along the human epididymis, transcriptome profiling was performed on 8 distinct epididymal regions from 3 donors. Microarray analysis was performed on a Gene Chip Human Clariom S (Affymetrix®) array representing 337 100 transcriptional variants encoded by 20 800 genes. Proximal segments 1 to 3 were distinguishable from the distal epididymal segments (4 to 8) as shown by unsupervised Principal Component Analysis. Transcripts from each segment with differentially expressed genes (DEGs) > 2-fold change and FDR < 0.05 were clustered in relation to their intensity profiles. While no DEGs were detected between segments 1–3 corresponding to the efferent ducts, 1140 DEGs were detected between efferent ducts (1–3) and the epididymis (4–8), 400 between caput (4–6) vs. corpus/cauda (7–8) and none between corpus (7) and cauda (8). Gene Ontology annotation revealed that up-regulated DEGs in the efferent ducts (1–3) were predominantly related to cilium assembly/movement and cell differentiation. The biological process terms fertilization, defense and immune responses were associated with caput epididymis (4–6) while spermatogenesis and protein binding were found all along the epididymis (4–8). In conclusion, the proximal human epididymis is exclusively occupied by efferent ducts with a distinct DEG profile compared with the downstream epididymal segments. Moreover, gene expression profiling revealed two regions in the human epididymis; the caput and the distal corpus/cauda region. Taken together, analysis of the human epididymal transcriptome reveals a limited DEG profile.