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:Co-infection of human papillomavirus (HPV) and human immunodeficiency virus type 1 (HIV-1) in women have a six-fold higher risk of developing cervical cancer compared to those without HIV. To evaluate how paracrine signals from HIV-infected T-cells remodeled the proteome of cervical epithelial cells in culture, primary CD4+ T cells isolated from PBMC-enriched leukapheresis products (leukopaks) from two healthy donors were infected or uninfected with a replication-competent pNL4-3 HIV-1 strain for 72 hours. Secretome from the CD4+ T cell cultures was used to stimulate the human HPV-negative cervical epithelial cell line, C33A, for 72 hours. Then, C33A cells were harvested, and cell lysates were digested and subjected to global quantitative mass spectrometry (MS) based abundance proteomics and phosphoproteomics analyses. Both proteomics and phosphoproteomics outputs were analysed using bioinformatics approaches. These datasets revealed altered expression of proteins in the MAPK, PI3K-AKT, and β-catenin signaling pathways. Additionally, MS phosphoproteomics analysis confirmed PI3K-AKT pathway activation in cervical cells exposed to conditioned media from HIV-1-infected T cells.
Project description:Persistent infection with human papillomavirus (HPV) is the primary cause of cervical cancer worldwide. Notably, women co-infected with HPV and human immunodeficiency virus type 1 (HIV-1) have a six-fold higher lifetime risk of developing cervical cancer compared to those without HIV, even when adhering to antiretroviral therapy (ART) and achieving T-cell reconstitution. While chronic HIV-1 infection is known to cause inflammation, how paracrine signals from immune cells alter signaling in cervical cells remain poorly understood. To address this, we conducted global transcriptomics analysis on cervical swabs from Kenyan women with HPV, stratified by HIV-1 and cancer status. Strikingly, women with HIV-1 showed cancer-like gene expression patterns in non-cancerous cervical epithelial cells. Complementary global mass spectrometry (MS) proteomics of cervical cells exposed to the secretome of HIV-1–infected primary CD4+ T-cells revealed altered expression of proteins in MAPK, PI3K-AKT, and β-catenin signaling pathways. Integrative network analyses of transcriptomic and proteomic datasets revealed that HIV-1 altered gene expression in key pathways known to drive cervical cancer, including genes commonly mutated in HIV-1-naïve disease. Notably, IRS-1, a key PI3K-AKT pathway activator, was found to be consistently upregulated in both participant samples and cell culture models, as were interferon-stimulated genes. Phosphoproteomics MS analysis confirmed PI3K-AKT pathway activation in cervical cells exposed to conditioned media from HIV-1-infected T-cells. Together, our findings uncover how HIV-1 reshapes cervical cell signaling via paracrine mechanisms and highlights the PI3K pathway as a potential therapeutic target in HIV-associated cervical cancer.
Project description:Photosynthetic induction, characterized by the lag in CO2 assimilation rates during transition from darkness to light, has traditionally been attributed to Rubisco activase activity and stomatal opening. Yet, the faster induction of photosynthesis in the 2-Cys peroxiredoxins (Prxs) mutant (2cpab) suggested a role for oxidative signals in regulating photosynthetic rates, although the underlying molecular mechanism remains unclear. SPEAR, a redox proteomics approach, was used to systematically map redox changes occurring during photosynthesis induction and to unravel the role of 2-Cys Prxs in shaping these redox alterations. No significant difference was observed in protein expression levels between WT and 2cpab plants, suggesting that protein abundance does not account for the 2cpab phenotype. During the transition from dark to low light, 82 and 54 cysteine-containing peptides were reduced or oxidized, respectively, in WT plants. Most redox-regulated cysteines in photosynthetic proteins were found oxidized in the dark and became reduced in response to light. A reverse pattern was observed among redox-regulated cysteines in proteins involved in starch degradation and chloroplast glycolysis, which shifted from a reduced to an oxidized state in response to light. These findings demonstrate the initiation of two opposing redox responses, affecting distinct sets of metabolic proteins during the induction phase. Remarkably, a significantly lower number of cysteines were reduced or oxidized in 2cpab plants, highlighting the crucial role 2-Cys Prxs play in shaping both signals. Taken together, rotational shifts between metabolic pathways during the photosynthesis induction phase are regulated by two opposing redox signals mediated by 2-Cys Prx activity.
Project description:Photosynthetic induction, characterized by the lag in CO2 assimilation rates during transition from darkness to light, has traditionally been attributed to Rubisco activase activity and stomatal opening. Yet, the faster induction of photosynthesis in the 2-Cys peroxiredoxins (Prxs) mutant (2cpab) suggested a role for oxidative signals in regulating photosynthetic rates, although the underlying molecular mechanism remains unclear. SPEAR, a redox proteomics approach, was used to systematically map redox changes occurring during photosynthesis induction and to unravel the role of 2-Cys Prxs in shaping these redox alterations. No significant difference was observed in protein expression levels between WT and 2cpab plants, suggesting that protein abundance does not account for the 2cpab phenotype. During the transition from dark to low light, 82 and 54 cysteine-containing peptides were reduced or oxidized, respectively, in WT plants. Most redox-regulated cysteines in photosynthetic proteins were found oxidized in the dark and became reduced in response to light. A reverse pattern was observed among redox-regulated cysteines in proteins involved in starch degradation and chloroplast glycolysis, which shifted from a reduced to an oxidized state in response to light. These findings demonstrate the initiation of two opposing redox responses, affecting distinct sets of metabolic proteins during the induction phase. Remarkably, a significantly lower number of cysteines were reduced or oxidized in 2cpab plants, highlighting the crucial role 2-Cys Prxs play in shaping both signals. Taken together, rotational shifts between metabolic pathways during the photosynthesis induction phase are regulated by two opposing redox signals mediated by 2-Cys Prx activity.
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.