RESUMO
Adult intestinal stem cells are located at the bottom of crypts of Lieberkühn, where they express markers such as LGR51,2 and fuel the constant replenishment of the intestinal epithelium1. Although fetal LGR5-expressing cells can give rise to adult intestinal stem cells3,4, it remains unclear whether this population in the patterned epithelium represents unique intestinal stem-cell precursors. Here we show, using unbiased quantitative lineage-tracing approaches, biophysical modelling and intestinal transplantation, that all cells of the mouse intestinal epithelium-irrespective of their location and pattern of LGR5 expression in the fetal gut tube-contribute actively to the adult intestinal stem cell pool. Using 3D imaging, we find that during fetal development the villus undergoes gross remodelling and fission. This brings epithelial cells from the non-proliferative villus into the proliferative intervillus region, which enables them to contribute to the adult stem-cell niche. Our results demonstrate that large-scale remodelling of the intestinal wall and cell-fate specification are closely linked. Moreover, these findings provide a direct link between the observed plasticity and cellular reprogramming of differentiating cells in adult tissues following damage5-9, revealing that stem-cell identity is an induced rather than a hardwired property.
Assuntos
Linhagem da Célula , Intestinos/citologia , Células-Tronco/citologia , Animais , Diferenciação Celular , Reprogramação Celular , Feminino , Feto/citologia , Mucosa Intestinal/citologia , Mucosa Intestinal/metabolismo , Intestinos/crescimento & desenvolvimento , Masculino , Camundongos , Receptores Acoplados a Proteínas G/metabolismo , Regeneração , Nicho de Células-TroncoRESUMO
BACKGROUND: Disordered fetal adrenal steroidogenesis can cause marked clinical effects including virilization of female fetuses. In postnatal life, adrenal disorders can be life-threatening due to the risk of adrenal crisis and must be carefully managed. However, testing explicit adrenal steroidogenic inhibitory effects of therapeutic drugs is challenging due to species-specific characteristics, and particularly the impact of adrenocorticotropic hormone (ACTH) stimulation on drugs targeting steroidogenesis has not previously been examined in human adrenal tissue. Therefore, this study aimed to examine the effects of selected steroidogenic inhibitors on human fetal adrenal (HFA) steroid hormone production under basal and ACTH-stimulated conditions. METHODS: This study used an established HFA ex vivo culture model to examine treatment effects in 78 adrenals from 50 human fetuses (gestational weeks 8-12). Inhibitors were selected to affect enzymes critical for different steps in classic adrenal steroidogenic pathways, including CYP17A1 (Abiraterone acetate), CYP11B1/2 (Osilodrostat), and a suggested CYP21A2 inhibitor (Efavirenz). Treatment effects were examined under basal and ACTH-stimulated conditions in tissue from the same fetus and determined by quantifying the secretion of adrenal steroids in the culture media using liquid chromatography-tandem mass spectrometry. Statistical analysis was performed on ln-transformed data using one-way ANOVA for repeated measures followed by Tukey's multiple comparisons test. RESULTS: Treatment with Abiraterone acetate and Osilodrostat resulted in potent inhibition of CYP17A1 and CYP11B1/2, respectively, while treatment with Efavirenz reduced testosterone secretion under basal conditions. ACTH-stimulation affected the inhibitory effects of all investigated drugs. Thus, treatment effects of Abiraterone acetate were more pronounced under stimulated conditions, while Efavirenz treatment caused a non-specific inhibition on steroidogenesis. ACTH-stimulation prevented the Osilodrostat-mediated CYP11B1 inhibition observed under basal conditions. CONCLUSIONS: Our results show that the effects of steroidogenic inhibitors differ under basal and ACTH-stimulated conditions in the HFA ex vivo culture model. This could suggest that in vivo effects of therapeutic drugs targeting steroidogenesis may vary in conditions where patients have suppressed or high ACTH levels, respectively. This study further demonstrates that ex vivo cultured HFAs can be used to evaluate steroidogenic inhibitors and thereby provide novel information about the local effects of existing and emerging drugs that targets steroidogenesis.
Assuntos
Glândulas Suprarrenais , Hormônio Adrenocorticotrópico , Feminino , Feto , Humanos , Esteroide 17-alfa-Hidroxilase , Esteroide 21-Hidroxilase , EsteroidesRESUMO
Although assisted reproductive technology has reduced the need for surgery for women with infertility, there is evidence to support, that targeted reproductive surgery can improve fertility and pregnancy outcomes. In the last decades, increased access to minimal invasive surgery has brought a new era to reproductive surgery. An integration of reproductive surgery in the fertility treatment is therefore recommended. The patient should be offered detailed information regarding the pros and cons before the surgical treatment, as the evidence in the field is sparse, which is discussed in this review.
Assuntos
Infertilidade Feminina , Feminino , Fertilidade , Humanos , Infertilidade Feminina/cirurgia , Gravidez , Resultado da Gravidez , Técnicas de Reprodução AssistidaRESUMO
Human organogenesis remains relatively unexplored for ethical and practical reasons. Here, we report the establishment of a single-cell transcriptome atlas of the human fetal pancreas between 7 and 10 post-conceptional weeks of development. To interrogate cell-cell interactions, we describe InterCom, an R-Package we developed for identifying receptor-ligand pairs and their downstream effects. We further report the establishment of a human pancreas culture system starting from fetal tissue or human pluripotent stem cells, enabling the long-term maintenance of pancreas progenitors in a minimal, defined medium in three-dimensions. Benchmarking the cells produced in 2-dimensions and those expanded in 3-dimensions to fetal tissue identifies that progenitors expanded in 3-dimensions are transcriptionally closer to the fetal pancreas. We further demonstrate the potential of this system as a screening platform and identify the importance of the EGF and FGF pathways controlling human pancreas progenitor expansion.
Assuntos
Técnicas de Cultura de Células/métodos , Organogênese , Pâncreas/embriologia , Células-Tronco Pluripotentes/fisiologia , Técnicas de Cultura de Tecidos/métodos , Feto Abortado , Animais , Comunicação Celular , Diferenciação Celular , Linhagem Celular , Conjuntos de Dados como Assunto , Embrião de Mamíferos , Fator de Crescimento Epidérmico/metabolismo , Fatores de Crescimento de Fibroblastos/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Camundongos , Pâncreas/citologia , RNA-Seq , Transdução de Sinais/fisiologia , Análise de Célula Única , Esferoides Celulares , TranscriptomaRESUMO
A consecutive series of 45 women with one or more previous second trimester deliveries, who had a pre-pregnancy transabdominal cerclage (TAC) from 1999 to July 2007, was followed until January 2008. Within the observation period 50 pregnancies occurred in 36 women. Seven resulted in first trimester abortions, none in second trimester abortions or deliveries, and six were on-going pregnancies. In the remaining 37 pregnancies the fetal salvage rate was 100%, and cesarean section was performed after 34 weeks (mean 36+5 weeks) in 36 (97%) pregnancies. One woman had three successful pregnancies following the procedure. No serious complications were associated with the application of TAC. One woman had a hysterectomy following cesarean section. Pre-pregnancy TAC is a procedure with few complications and excellent outcome. The method may be considered in women with a second trimester fetal loss, when cervical incompetence cannot be ruled out.
Assuntos
Aborto Habitual/prevenção & controle , Cerclagem Cervical/métodos , Complicações Pós-Operatórias/epidemiologia , Nascimento Prematuro/prevenção & controle , Incompetência do Colo do Útero/cirurgia , Adulto , Cerclagem Cervical/efeitos adversos , Cesárea , Feminino , Idade Gestacional , Humanos , Gravidez , Resultado da Gravidez , Nascimento Prematuro/epidemiologia , Fatores de Risco , Fatores de Tempo , Falha de TratamentoRESUMO
OBJECTIVE: By focussing on differences in the mural granulosa cell (MGC) and cumulus cell (CC) transcriptomes from follicles resulting in competent (live birth) and non-competent (no pregnancy) oocytes the study aims on defining a competence classifier expression profile in the two cellular compartments. DESIGN: A case-control study. SETTING: University based facilities for clinical services and research. PATIENTS: MGC and CC samples from 60 women undergoing IVF treatment following the long GnRH-agonist protocol were collected. Samples from 16 oocytes where live birth was achieved and 16 age- and embryo morphology matched incompetent oocytes were included in the study. METHODS: MGC and CC were isolated immediately after oocyte retrieval. From the 16 competent and non-competent follicles, mRNA was extracted and expression profile generated on the Human Gene 1.0 ST Affymetrix array. Live birth prediction analysis using machine learning algorithms (support vector machines) with performance estimation by leave-one-out cross validation and independent validation on an external data set. RESULTS: We defined a signature of 30 genes expressed in CC predictive of live birth. This live birth prediction model had an accuracy of 81%, a sensitivity of 0.83, a specificity of 0.80, a positive predictive value of 0.77, and a negative predictive value of 0.86. Receiver operating characteristic analysis found an area under the curve of 0.86, significantly greater than random chance. When applied on 3 external data sets with the end-point outcome measure of blastocyst formation, the signature resulted in 62%, 75% and 88% accuracy, respectively. The genes in the classifier are primarily connected to apoptosis and involvement in formation of extracellular matrix. We were not able to define a robust MGC classifier signature that could classify live birth with accuracy above random chance level. CONCLUSION: We have developed a cumulus cell classifier, which showed a promising performance on external data. This suggests that the gene signature at least partly include genes that relates to competence in the developing blastocyst.