Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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    A comparative analysis of human adult testicular cells expressing stem Leydig cell markers in the interstitium, vasculature, and peritubular layer
    Eliveld, Jitske ; Daalen, Saskia K.M. van; Winter-Korver, Cindy M. de; Veen, Fulco van der; Repping, Sjoerd ; Teerds, Katja ; Pelt, Ans M.M. van - \ 2020
    Andrology (2020). - ISSN 2047-2919
    human testis - markers - propagation - stem Leydig cells

    Background: Origin of human adult Leydig cells (ALCs) is not well understood. This might be partly due to limited data available on the identification and location of human precursor and stem Leydig cells (SLCs) which hampers the study on the development of ALCs. Objectives: The aim of the present study was to investigate whether described human (PDGFRα, NGFR) and rodent (NES, PDGFRα, THY1, NR2F2) SLC markers are expressed by a common cell population within human adult testicular interstitial cells in vivo and before and after in vitro propagation. Materials and methods: Immunohistochemical analyses were used to identify localization of human adult testicular interstitial cells expressing described SLC markers. Next, interstitial cells were isolated and cultured. The percentage of cells expressing one or more SLC markers was determined before and after culture using flow cytometry. Results: NR2F2 and PDGFRα were present in peritubular, perivascular, and Leydig cells, while THY1 was expressed in peritubular and perivascular cells. Although NES and NGFR were expressed in endothelial cells, co-localization with PDGFRα was found for both in vitro, although for NGFR only after culture. All marker positive cells were able to undergo propagation in vitro. Discussion: The partly overlap in localization and overlap in expression in human testicular cells indicate that PDGFRα, NR2F2, and THY1 are expressed within the same ALC developmental lineage from SLCs. Based on the in vitro results, this is also true for NES and after in vitro propagation for NGFR. Conclusion: Our results that earlier described SLC markers are expressed in overlapping human interstitial cell population opens up further research strategies aiming for a better insight in the Leydig cell lineage and will be helpful for development of strategies to cure ALC dysfunction.

    Primary human testicular PDGFRα+ cells are multipotent and can be differentiated into cells with Leydig cell characteristics in vitro
    Eliveld, J. ; Berg, E.A. van den; Chikhovskaya, J.V. ; Daalen, S.K.M. van; Winter-Korver, C.M. de; Veen, F. van der; Repping, S. ; Teerds, K. ; Pelt, A.M.M. van - \ 2019
    Human Reproduction 34 (2019)9. - ISSN 0268-1161 - p. 1621 - 1631.
    mesenchymal stromal cell - PDGFRα - stem Leydig cell - steroidogenesis - testis

    STUDY QUESTION: Is it possible to differentiate primary human testicular platelet-derived growth factor receptor alpha positive (PDGFRα+) cells into functional Leydig cells? SUMMARY ANSWER: Although human testicular PDGFRα+ cells are multipotent and are capable of differentiating into steroidogenic cells with Leydig cell characteristics, they are not able to produce testosterone after differentiation. WHAT IS KNOWN ALREADY: In rodents, stem Leydig cells (SLCs) that have been identified and isolated using the marker PDGFRα can give rise to adult testosterone-producing Leydig cells after appropriate differentiation in vitro. Although PDGFRα+ cells have also been identified in human testicular tissue, so far there is no evidence that these cells are true human SLCs that can differentiate into functional Leydig cells in vitro or in vivo. STUDY DESIGN, SIZE, DURATION: We isolated testicular cells enriched for interstitial cells from frozen-thawed fragments of testicular tissue from four human donors. Depending on the obtained cell number, PDGFRα+-sorted cells of three to four donors were exposed to differentiation conditions in vitro to stimulate development into adipocytes, osteocytes, chondrocytes or into Leydig cells. We compared their cell characteristics with cells directly after sorting and cells in propagation conditions. To investigate their differentiation potential in vivo, PDGFRα+-sorted cells were transplanted in the testis of 12 luteinizing hormone receptor-knockout (LuRKO) mice of which 6 mice received immunosuppression treatment. An additional six mice did not receive cell transplantation and were used as a control. PARTICIPANTS/MATERIALS, SETTING, METHODS: Human testicular interstitial cells were cultured to Passage 3 and FACS sorted for HLA-A,B,C+/CD34-/PDGFRα+. We examined their mesenchymal stromal cell (MSC) membrane protein expression by FACS analyses. Furthermore, we investigated lineage-specific staining and gene expression after MSC trilineage differentiation. For the differentiation into Leydig cells, PDGFRα+-sorted cells were cultured in either proliferation or differentiation medium for 28 days, after which they were stimulated either with or without hCG, forskolin or dbcAMP for 24 h to examine the increase in gene expression of steroidogenic enzymes using qPCR. In addition, testosterone, androstenedione and progesterone levels were measured in the culture medium. We also transplanted human PDGFRα+-sorted testicular interstitial cells into the testis of LuRKO mice. Serum was collected at several time points after transplantation, and testosterone was measured. Twenty weeks after transplantation testes were collected for histological examination. MAIN RESULTS AND THE ROLE OF CHANCE: From primary cultured human testicular interstitial cells at Passage 3, we could obtain a population of HLA-A,B,C+/CD34-/PDGFRα+ cells by FACS. The sorted cells showed characteristics of MSC and were able to differentiate into adipocytes, chondrocytes and osteocytes. Upon directed differentiation into Leydig cells in vitro, we observed a significant increase in the expression of HSD3B2 and INSL3. After 24 h stimulation with forskolin or dbcAMP, a significantly increased expression of STAR and CYP11A1 was observed. The cells already expressed HSD17B3 and CYP17A1 before differentiation but the expression of these genes were not significantly increased after differentiation and stimulation. Testosterone levels could not be detected in the medium in any of the stimulation conditions, but after stimulation with forskolin or dbcAMP, androstenedione and progesterone were detected in culture medium. After transplantation of the human cells into the testes of LuRKO mice, no significant increase in serum testosterone levels was found compared to the controls. Also, no human cells were identified in the interstitium of mice testes 20 weeks after transplantation.N/A. LIMITATIONS, REASONS FOR CAUTION: This study was performed using tissue from only four donors because of limitations in donor material. Because of the need of sufficient cell numbers, we first propagated cells to passage 3 before FACS of the desired cell population was performed. We cannot rule out this propagation of the cells resulted in loss of stem cell properties. WIDER IMPLICATIONS OF THE FINDINGS: A lot of information on Leydig cell development is obtained from rodent studies, while the knowledge on human Leydig cell development is very limited. Our study shows that human testicular interstitial PDGFRα+ cells have different characteristics compared to rodent testicular PDGFRα+ cells in gene expression levels of steroidogenic enzymes and potential to differentiate in adult Leydig cells under comparable culture conditions. This emphasizes the need for confirming results from rodent studies in the human situation to be able to translate this knowledge to the human conditions, to eventually contribute to improvements of testosterone replacement therapies or establishing alternative cell therapies in the future, potentially based on SLCs. STUDY FUNDING/COMPETING INTEREST(S): This study was funded by Amsterdam UMC, location AMC, Amsterdam, the Netherlands. All authors declare no competing interests.

    Roll dynamics of a ship sailing in large amplitude head waves
    Daalen, E.F.G. ; Gunsing, M. ; Grasman, J. ; Remmert, J. - \ 2014
    Journal of Engineering Mathematics 89 (2014)1. - ISSN 0022-0833 - p. 137 - 146.
    astern seas
    Some ship types may show significant rolling when sailing in large-amplitude (near) head waves. The dynamics of the ship are such that the roll motion is affected by the elevation of the encountering waves. If the natural roll period (without forcing) is about half the period of the forcing by the waves, then a stationary solution will have an amplitude that is much larger than for other forcing frequencies. This phenomenon is called parametric resonance. For certain hull shape types the transverse stability may vary considerably due to the waves passing the ship. Moreover, near head waves will also have a direct effect on the roll dynamics. For these processes a differential equation model—a Mathieu type of equation—is formulated. Furthermore, the waves considered are of a type that is encountered in open seas. As a parameterization of these waves the Pierson–Moskowitz spectrum is used. The risk that the ship will reach a critical state is characterized by the time of arrival at this state, starting from an arbitrary pattern of the waves and the dynamic state of the vessel in the stationary situation. Large-scale Monte Carlo simulations of this process are carried out. The percentiles of the arrival time distribution indicate the risk of significant rolling to which the vessel is exposed. Furthermore, a method is proposed to estimate the maximum roll angle in a stationary state by taking into consideration only the part of the wave spectrum that relates to the state of parametric resonance. The result is compared with the outcome of the large-scale Monte Carlo simulations.
    Dynamical models of extreme rolling of vessels in head waves
    Archer, C. ; Daalen, E.F.G. ; Dobberschütz, S. ; Godeau, M.F. ; Grasman, J. ; Gunsing, M. ; Muskulus, M. ; Pischanskyy, A. ; Wakker, M. - \ 2009
    - p. 1 - 22.
    Het belang van cultureel kapitaal. Ondernemers en het particulier onderwijs
    Weenink, D. - \ 2006
    In: Over gelijkheid en verschil / Brinkgreve, Chr., van Daalen, R., Amsterdam - Antwerpen : Uitgeverij Het Spinhuis - ISBN 9789055892761 - p. 98 - 107.
    How did 'bog oaks' grow? First answers from the excavation of a mire woodland in Ypenburg, The Netherlands
    Daalen, S. van; Kooistra, L.I. ; Sass, U.G.W. - \ 2003
    In: TRACE. Tree Rings in Archaeology, Climatology and Ecology. Vol. 1. - Bonn/Juelich Duitsland : Forschungszentrum Juelich GmbH, Zentralbibliothek - ISBN 9783893363230 - p. 82 - 86.
    Van liefdadigheid naar verzorgingsstaat.
    Daalen, R. van; Hoog, K. de; Pott-Buter, H. ; Regt, A. de; Tijdens, K. - \ 1998
    In: Vrouwen, leven en werk in de twintigste eeuw / Pott-Buter, H., Tijdens, K., Amsterdam : Amsterdam University Press - p. 81 - 108.
    Rubber toplaag verbetert welzijn vleesstieren
    Plomp, M. ; Smits, A.C. ; Goedegebuure, S.A. ; Daalen, R. van - \ 1994
    Praktijkonderzoek / Praktijkonderzoek Rundvee, Schapen en Paarden (PR), Waiboerhoeve 7 (1994)1. - ISSN 0921-8874 - p. 35 - 37.
    huisvesting, dieren - dierenwelzijn - vleesvee - bouwconstructie - stieren (bulls) - plafonds - vloeren - roostervloeren - rubber - rubberindustrie - stallen - muren - animal housing - animal welfare - beef cattle - building construction - bulls - ceilings - floors - grid floors - rubber - rubber industry - stalls - walls
    Piemontese kruislingstieren op een rubber toplaag vertoonden aanzienlijk minder afwijkend gedrag bij het gaan staan en liggen, ze waren actiever en hadden minder ernstige gewrichtsbeschadigingen aan de voorknie.
    Bijvoeding MKS en CCM in weideperiode
    Bruins, W.J. ; Daalen, R. van; Schooten, H.A. van - \ 1992
    Praktijkonderzoek / Praktijkonderzoek Rundvee, Schapen en Paarden (PR), Waiboerhoeve 5 (1992)2. - ISSN 0921-8874 - p. 49 - 51.
    dierhouderij - samenstelling - melkvee - melkveehouderij - bedrijfsresultaten in de landbouw - voer - voedergewassen - voederpeulvruchten - rentabiliteit - animal husbandry - composition - dairy cattle - dairy farming - farm results - feeds - fodder crops - fodder legumes - profitability
    In dit artikel wordt ingegaan op de effecten van CCM en MKS op de melkproductie en melksamenstelling gebaseerd op onderzoek op de ROC's Aver Heino en De Vlierd.
    Onderzoek op ROC De Vlierd
    Daalen, R. van; Wismeijer, D.J. - \ 1991
    Praktijkonderzoek / Praktijkonderzoek Rundvee, Schapen en Paarden (PR), Waiboerhoeve 4 (1991)6. - ISSN 0921-8874 - p. 44 - 47.
    Onderzoek wordt gedaan met het melkvee, de vleesvaarzen, de vleesstieren, het grasland en de mais. Per tak worden de projecten waar momenteel op De Vlierd aan gewerkt wordt kort beschreven.
    Bijdrage tot de kennis van de chemische en botanische samenstelling van het hooi en van den invloed, welke enkele meststoffen daarop uitoefenen
    Daalen, C.K. van - \ 1928
    Wageningen University. Promotor(en): J.H. Aberson. - Utrecht : P. den Boer - 188
    hooi - groenvoeders - cum laude - hay - green fodders
    This study was concerned with the most important results of some fertilizer trials on grassland. It was established how the amount of hay gained from the trial fields was extremely divergent. The factors causing these differences and the influence of N, P and K on the chemical and botanical composition of the hay were examined. This was considered separately for each fertilizer. On the chemical composition, attention was especially to N, P, K, Ca and total ash. Part of the trial was on the influence of stage of cutting.

    This trial has been of great importance in the further development of grassland research in the Netherlands.

    Varieteits- en conserveeringsproeven met mangelwortels
    Sjollema, B. ; Daalen, C.K. van - \ 1907
    's-Gravenhage : Gebrs. J. & H. van Langenhuyzen (Verslagen van landbouwkundige onderzoekingen der rijkslandbouwproefstations 02.02) - 20
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