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Biology subjects

Gargett, C. E.

Publications and source records attributed to Gargett, C. E..

4 recordsLinked to original sources

Epithelial stem cells in the premenopausal human vagina

The vagina undergoes physiologic changes across the menstrual cycle, pregnancy, birth and menopause. Most women will experience vaginal dysfunction at some point during their lives and treatment options are limited. The cyclic regeneration of the vaginal epithelium during each menstrual cycle suggests it is a stem-cell based tissue; however, human vaginal epithelial stem cells (veSCs) have not been identified. We utilized in vitro colony forming and organoid assays to confirm that cells in the human vaginal epithelium have self-renewal and differentiation potential. Specifically, we determined that stem cell activity resides in the ITGA6+ and NGFR+ fractions of the basal epithelium. We performed single-cell RNA sequencing to identify the distinct cellular compartments of the full thickness human vagina, including spatially distinct populations comprising layers of the stratified vaginal epithelium. Markers of these cells within the vaginal epithelium were validated by immunohistochemistry. CD9+ITGA6+NGFR+ and CD9+ITGA6+NGFR- cells were capable of efficient colony formation but only the CD9+ITGA6+NGFR+ fraction produced organoids containing basal, intermediate and superficial layers of the vaginal epithelium. We characterized the premenopausal human vagina at single cell resolution, validated markers and assays to test veSC developmental potential, and identified putative stem cells that may open new avenues for treating vaginal dysfunction.

cell biology↗

Molecular signature of human endometrial stem/progenitor cells at the single cell level

Human endometrium sheds and regenerates each month during the menstrual cycle. N-cadherin+ (CDH2) glandular epithelial progenitors and SUSD2+ MSC and their niches have been identified but their signaling interactions remain unknown. SSEA1+ epithelial cells resurface the endometrium generating a new luminal epithelium each cycle. Based on these markers, we characterised the gene expression of human endometrial stem/progenitor cell-enriched populations derived from FACSorted hysterectomy endometrium by scRNAseq. Two of 10 epithelial clusters contained CDH2+SOX9+ cells with high TRH and IHH expression. N-cadherin and IHH, and SSEA1 and Hedgehog coreceptor BOC immunocolocalised in the basal layer of endometrial glands from which the new functional layer glands regenerate each menstrual cycle. Two of six mesenchymal clusters contained SUSD2+ MSC, one with high MUSTN1 expression. Epithelial progenitors and endometrial MSC transitioned to their respective progeny. We provide new insights into human endometrial stem/progenitor cell signaling pathways and niche interactions regulating their function. HighlightsO_LIEnriching cell suspensions of human endometrial cells from hysterectomy tissues with CDH2+ epithelial progenitors, SSEA-1+ basalis epithelial cells and SUSD2+ perivascular MSC enabled their gene profiling at the single cell level. C_LIO_LIMultiple cell fate trajectory analyses showed that CDH2+SOX9+ epithelial cells and SUSD2+MYH11+MCAM+MUSTN1+ MSC are the progenitors for human endometrial glandular and luminal epithelial cells, and stromal vascular cells, respectively. C_LIO_LIEnriched TRH expression in human endometrial epithelial progenitors suggests a role in their progenitor function. C_LIO_LIInteraction between IHH of SOX9+ human endometrial epithelial progenitors with basalis fibroblasts and decidualized stroma and co-receptor BOC suggests IHH signalling may have a role in basalis epithelial migration to repair the luminal epithelium during menses. C_LI eTOC blurbGargett and colleagues provide a molecular signature of human endometrial stem/progenitor cells by enriching 4 stem/progenitor populations from hysterectomies using known markers for scRNAseq analysis. The two epithelial and two MSC progenitor states identified transitioned to their differentiated progeny. IHH was validated as a key signalling molecule of epithelial progenitors in basal glands that interacted with BOC co-receptors.

molecular biology↗

M2 Macrophages are Major Mediators of Germline Risk of Endometriosis and Explain Pleiotropy with Comorbid Traits

Endometriosis is a common gynecologic condition that causes chronic life-altering symptoms including pain, infertility, and elevated cancer risk. There is an urgent need for new non-hormonal targeted therapeutics to treat endometriosis, but until very recently, the cellular and molecular signatures of endometriotic lesions were undefined, severely hindering the development of clinical advances. Integrating inherited risk data from analyses of >450,000 individuals with [~]350,000 single cell transcriptomes from 21 patients, we uncover M2-macrophages as candidate drivers of disease susceptibility, and nominate IL1 signaling as a central hub impacted by germline genetic variation associated with endometriosis. Extensive functional follow-up confirmed these associations and revealed a pleiotropic role for this pathway in endometriosis. Population-scale expression quantitative trail locus analysis demonstrated that genetic variation controlling IL1A expression is also associated with endometriosis risk variants. Manipulation of IL1 signaling in state-of-the-art in vitro decidualized assembloids impacted epithelial differentiation, and in an in vivo endometriosis model, treatment with anakinra (an interleukin-1 receptor antagonist) resulted in a significant, dose-dependent reduction in both spontaneous pain and evoked pain. Together these studies highlight non-diagnostic cell types as central to endometriosis susceptibility and support IL1 signaling as an important actionable pathway for this disease.

immunology↗

Impact of sustained TGFβ receptor inhibition on chromatin accessibility and gene expression in cultured human endometrial MSC

Endometrial mesenchymal stem cells (eMSC) drive the extraordinary regenerative capacity of the human endometrium. Clinical application of eMSC for therapeutic purposes is hampered by spontaneous differentiation and cellular senescence upon large-scale expansion in vitro. A83-01, a selective transforming growth factor-{beta} receptor (TGF{beta}-R) inhibitor, promotes pharmacological expansion of eMSC in culture by blocking differentiation and senescence, but the underlying mechanisms are incompletely understood. In this study, we combined RNA-seq and ATAC-seq to study the impact of sustained TGF{beta}-R inhibition on gene expression and chromatin architecture of eMSC. Treatment of primary eMSC with A83-01 for 5 weeks resulted in differential expression of 1,463 genes. Gene ontology analysis showed enrichment of genes implicated in cell growth whereas extracellular matrix genes and genes involved in cell fate commitment were downregulated. ATAC-seq analysis demonstrated that sustained TGF{beta}-R inhibition results in opening and closure of 3,555 and 2,412 chromatin loci, respectively. Motif analysis revealed marked enrichment of retinoic acid receptor (RAR) binding sites, which was paralleled by the induction of RARB, encoding retinoic acid receptor beta (RAR{beta}). Selective RAR{beta} inhibition attenuated proliferation and clonogenicity of A83-01 treated eMSC. Taken together, our study provides new insights into the gene networks and genome-wide chromatin changes that underpin maintenance of an undifferentiated phenotype of eMSC in prolonged culture. Significance statementCycling human endometrium is a rich source of adult stem/progenitor cells that could be exploited for clinical purposes. Small molecules, such as A83-01, that modulate cell identity may open new avenues to maintain the functional properties of eMSC upon expansion in culture. By integrating complementary genome-wide profiling techniques, we mapped the dynamic changes in chromatin landscape and gene expression in response to prolonged A83-01 treatment of eMSC. Our findings provide new insights into the mechanisms of action of TGF{beta}-R inhibition that may lead to the development of more targeted pharmacological approaches for MSC expansion.

cell biology↗