Gametes are cells that have the unique ability to give rise to new individuals as well as transmit (epi)genetic information across generations. Generation of functionally competent gametes, oocytes... Show moreGametes are cells that have the unique ability to give rise to new individuals as well as transmit (epi)genetic information across generations. Generation of functionally competent gametes, oocytes and sperm cells, depends to some extent on several fundamental processes that occur during fetal development. Direct studies on human fetal germ cells remain hindered by ethical considerations and inaccessibility to human fetal material. Therefore, the majority of our current knowledge of germ cell development still comes from an invaluable body of research performed using different mammalian species. During the last decade, our understanding of human fetal germ cells has increased due to the successful use of human pluripotent stem cells to model aspects of human early gametogenesis and advancements on single-cell omics. Together, this has contributed to determine the cell types and associated molecular signatures in the developing human gonads. In this review, we will put in perspective the knowledge obtained from several mammalian models (mouse, monkey, pig). Moreover, we will discuss the main events during human fetal (female) early gametogenesis and how the dysregulation of this highly complex and lengthy process can link to infertility later in life. Show less
Maurice-Stam, H.; Erp, L.M.E. van; Maas, A.; Oers, H.A. van; Kremer, L.C.M.; Dulmen-den Broeder, E. van; ... ; Dutch LATER Study Grp 2022
Purpose The study aimed to compare the psychosocial development of young adult survivors of childhood cancer (YACCS) with a norm group of young adults from the general population. Methods From 2017... Show morePurpose The study aimed to compare the psychosocial development of young adult survivors of childhood cancer (YACCS) with a norm group of young adults from the general population. Methods From 2017 to 2020, 558 YACCS (18-30 years, 51% female, 10.9% CNS cancer) who participated in the Dutch Childhood Cancer Survivor Study (DCCSS) LATER cohort (diagnosed 1963-2001) part 2 completed the Course of Life Questionnaire (CoLQ), assessing the achievement of milestones. Items were grouped into the scales autonomy, psychosexual, and social development. Differences between YACCS and norm group were examined with ANOVA and Cohen's d (CoLQ scales) and with logistic regression analysis and odds ratio (OR) (CoLQ items), for the total group and YACCS of CNS cancer. Results The total group of YACCS did not report a less favorable psychosocial development than the norm group. YACCS of CNS cancer scored lower than the norm group (p < 0.001) on the scales autonomy (d = - 0.36) and psychosexual (d = - 0.46). Additionally, on half of the items of autonomy (0.25 <= OR <= 0.34), psychosexual (0.30 <= OR <= 0.48), and social (0.23 <= OR <= 0.47) development, YACCS of CNS cancer were less likely (p < 0.01) than the norm group to have achieved the milestones. Conclusion Overall, psychosocial development of YACCS was as favorable as the norm, but YACCS of CNS cancer were at risk of an unfavorable psychosocial development in all domains. Monitoring psychosocial development should be included in the standards of psychosocial care, especially for CNS cancer patients and survivors, to be able to trace delay. Personalized interventions should be offered to improve the psychosocial development in an early stage. Show less
Patients with a congenital bicuspid aortic valve (BAV), a valve with two instead of three aortic leaflets, have an increased risk of developing thoracic aneurysms and aortic dissection. The... Show morePatients with a congenital bicuspid aortic valve (BAV), a valve with two instead of three aortic leaflets, have an increased risk of developing thoracic aneurysms and aortic dissection. The mechanisms underlying BAV-associated aortopathy are poorly understood. This study examined BAV-associated aortopathy in Nos3(-/-) mice, a model with congenital BAV formation. A combination of histological examination and in vivo ultrasound imaging was used to investigate aortic dilation and dissections in Nos3(-/-) mice. Moreover, cell lineage analysis and single-cell RNA sequencing were used to observe the molecular anomalies within vascular smooth muscle cells (VSMCs) of Nos3(-/-) mice. Spontaneous aortic dissections were found in ascending aortas located at the sinotubular junction in similar to 13% of Nos3(-/-) mice. Moreover, Nos3(-/-) mice were prone to developing aortic dilations in the proximal and distal ascending aorta during early adulthood. Lower volumes of elastic fibres were found within vessel walls of the ascending aortas of Nos3(-/-) mice, as well as incomplete coverage of the aortic inner media by neural crest cell (NCC)-derived VSMCs. VSMCs of Nos3(-/-) mice showed downregulation of 15 genes, of which seven were associated with aortic aneurysms and dissections in the human population. Elastin mRNA was most markedly downregulated, followed by fibulin-5 expression, both primary components of elastic fibres. This study demonstrates that, in addition to congenital BAV formation, disrupted endothelial-mediated nitric oxide (NO) signalling in Nos3(-/-) mice also causes aortic dilation and dissection, as a consequence of inhibited elastic fibre formation in VSMCs within the ascending aorta. Show less
Balak, J.R.A.; Juksar, J.; Carlotti, F.; Nigro, A. lo; Koning, E.J.P. de 2019
Purpose of Review Novel 3D organoid culture techniques have enabled long-term expansion of pancreatic tissue. This review comprehensively summarizes and evaluates the applications of primary tissue... Show morePurpose of Review Novel 3D organoid culture techniques have enabled long-term expansion of pancreatic tissue. This review comprehensively summarizes and evaluates the applications of primary tissue-derived pancreatic organoids in regenerative studies, disease modelling, and personalized medicine.Recent Findings Organoids derived from human fetal and adult pancreatic tissue have been used to study pancreas development and repair. Generated adult human pancreatic organoids harbor the capacity for clonal expansion and endocrine cell formation. In addition, organoids have been generated from human pancreatic ductal adenocarcinoma in order to study tumor behavior and assess drug responses.Summary Pancreatic organoids constitute an important translational bridge between in vitro and in vivo models, enhancing our understanding of pancreatic cell biology. Current applications for pancreatic organoid technology include studies on tissue regeneration, disease modelling, and drug screening. Show less
Several studies have highlighted the uniqueness of the human immune system in early life. Due to the scarceness of human fetal tissues and technical limitations, a system-wide and detailed... Show moreSeveral studies have highlighted the uniqueness of the human immune system in early life. Due to the scarceness of human fetal tissues and technical limitations, a system-wide and detailed phenotypical characterization of the composition and development of the human fetal immune system was lacking. Here, I delineate the composition and development of the human fetal immune system using an array of advanced high-throughput technologies. First, mass cytometry analysis of the innate lymphoid cells revealed a previously unrecognized subset named int-ILC in the fetal intestine, which can give rise to NK cells and ILC3s. Moreover, by combining the acquired datasets from (imaging-) mass cytometry, single-cell RNA-sequencing and TCR sequencing with advanced computational analysis tools and functional analysis this revealed that memory-like CD4+ T cells were already generated in the developing human fetal intestine, indicative of in utero exposure to foreign antigens. Additionally, (imaging-) mass cytometry analysis of the immune cells in the fetal intestine, spleen and liver revealed an early-life immune compartmentalization in these different fetal tissues. Overall, our results deepens the understanding of prenatal immunity and may ultimately be useful for the development of “early” intervention strategies to prevent the development of immune mediated diseases later in life. Show less
Klapwijk, E.T.; Kamp, F. van de; Meulen, M. van der; Peters, S.; Wierenga, L.M. 2019
Performing quality control to detect image artifacts and data-processing errors is crucial in structural magnetic resonance imaging, especially in developmental studies. Currently, many studies... Show morePerforming quality control to detect image artifacts and data-processing errors is crucial in structural magnetic resonance imaging, especially in developmental studies. Currently, many studies rely on visual inspection by trained raters for quality control. The subjectivity of these manual procedures lessens comparability between studies, and with growing study sizes quality control is increasingly time consuming. In addition, both inter-rater as well as intra-rater variability of manual quality control is high and may lead to inclusion of poor quality scans and exclusion of scans of usable quality. In the current study we present the Qoala-T tool, which is an easy and free to use supervised-learning model to reduce rater bias and misclassification in manual quality control procedures using FreeSurfer-processed scans. First, we manually rated quality of N = 784 FreeSurfer-processed T1-weighted scans acquired in three different waves in a longitudinal study. Different supervised-learning models were then compared to predict manual quality ratings using FreeSurfer segmented output data. Results show that the Qoala-T tool using random forests is able to predict scan quality with both high sensitivity and specificity (mean area under the curve (AUC) = 0.98). In addition, the Qoala-T tool was also able to adequately predict the quality of two novel unseen datasets (total N = 872). Finally, analyses of age effects showed that younger participants were more likely to have lower scan quality, underlining that scan quality might confound findings attributed to age effects. These outcomes indicate that this procedure could further help to reduce variability related to manual quality control, thereby benefiting the comparability of data quality between studies. Show less
In this thesis we aimed to get insight in how the methylome is established during development and subsequently degenerates during ageing using an integrative approach to the analysis of DNA... Show moreIn this thesis we aimed to get insight in how the methylome is established during development and subsequently degenerates during ageing using an integrative approach to the analysis of DNA methylation in conjunction with other levels of genomics data. The first two empirical chapters of this thesis describe the establishment and the maintenance of the epigenome during fetal development and in later life in multiple tissues. In the subsequent two chapters we investigated the loss of control over the methylome in blood and other tissues. Show less
Gurp, L. van; Loomans, C.J.M.; Krieken, P.P. van; Dharmadhikari, G.; Jansen, E.; Ringnalda, F.C.A.S.; ... ; Koning, E.J.P. de 2016
Dexamethasone (DEX), a synthetic glucocorticoid, has been used to treat respiratory distress syndrome in prematurely born infants. Despite the important short-term benefit on lung function, there... Show moreDexamethasone (DEX), a synthetic glucocorticoid, has been used to treat respiratory distress syndrome in prematurely born infants. Despite the important short-term benefit on lung function, there is growing concern about the long-term outcome of this treatment, since follow-up studies of prematurely born infants have shown lasting adverse neurodevelopmental effects. Since the mechanism underlying these neurodevelopmental impairments is largely unknown, the aim of the present study was (i) to investigate the acute effects of neonatal DEX treatment on the developing brain; and (ii) to block specifically the effects of DEX on the brain by central administration of the glucocorticoid receptor (GR) antagonist mifepristone. Long Evans rat pups were injected subcutaneously with tapering doses of DEX or saline (SAL) on postnatal days (pnd) 1, 2 and 3. Separate groups received intracerebroventricular injections with mifepristone prior to DEX treatment. On pnd 4 and 10, pups were sacrificed and brains collected for analysis of cell proliferation (Ki-67) and astrogliosis (GFAP). We report that neonatal DEX treatment reduced hippocampal cell proliferation on pnd 4, an effect that was normalized by pnd 10. Although on pnd 4, GFAP expression was not affected, DEX treatment caused a significant reduction in the number and density of astrocytes in hippocampus and corpus callosum on pnd 10, which was normalized by mifepristone pre-treatment. These acute alterations in the neonate brain might underlie later functional impairments reported in DEX-treated animals and humans and further illustrate the impact of early GR activation on brain development. (C) 2012 Elsevier B.V. All rights reserved. Show less
