Prof. Dr. med. Dr. rer. nat.
Hans-Werner Denker
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Hans-Werner Denker – University Duisburg-Essen

Chair of Anatomy and Developmental Biology

Prof. H.-W. Denker Hans-Werner Denker, Prof. Dr. med. Dr. rer. nat.
Institute of Anatomy, Medical Faculty, University Duisburg-Essen (Germany)
Retired since March 2006

Research Topics

Cell and developmental biology:
Embryo implantation; cell biology of uterine epithelium and its receptive state; trophoblast; in vitro investigations of trophoblastic and choriocarcinoma cell lines; cell-cell interactions, cell-matrix interactions, cell differentiation, mechanisms of invasion.
Developmental biology of early mammalian embryos.

Stem cells:
Developmental potential (totipotency, omnipotency, pluripotency), embryoids, blastoids, gastruloids, ethics.

Recent own Publications (view all)

  • DENKER, H.-W.:
    Embryoids, models, embryos? We need to take a new look at legal norms concerning the beginning of organismic development.
    Molec. Hum. Reprod. 30(1): gaad047 (2024). DOI: 10.1093/molehr/gaad047
    PubMed   MHR   pdf-download (615 KB)
  • DENKER, H.-W.:
    Stem Cell-Derived Organoids, Embryoids, and Embryos: Advances in Organismic Development In Vitro Force Us to Re-Focus on Ethical and Legal Aspects of Model Choice.
    Organoids 2: 231-238 (2023). DOI: 10.3390/organoids2040018
    Organoids Website   pdf-download (247 KB)
  • DENKER, H.-W.:
    Wir brauchen eine Neudefinition des Begriffs "Embryo".
    Deutsches Ärzteblatt 120 (33-34): A-1383 / B-1191 (21. August 2023).
    Deutsches Ärzteblatt   pdf-download (315 KB)
    Twenty Years on for The Epithelial-Mesenchymal Transition International Association (TEMTIA): An Interview with Co-Founders Erik Thompson and Donald Newgreen.
    Cells Tissues Organs 211(2): 252-260 (2022). DOI: 10.1159/000518250
    PubMed   CTO Website (free access)
  • DENKER, H.-W.:
    Autonomy in the Development of Stem Cell-Derived Embryoids: Sprouting Blastocyst-Like Cysts, and Ethical Implications.
    Cells 10: 1461 (2021) (Open Access). DOI: 10.3390/cells10061461
    PubMed   Cells Website   pdf-download (1.54 MB)
  • DENKER, H.-W.:
    Rise of the rabbit model for implantation research. A commemoration of the scientific work of Bent G. Boving (1920-2019).
    Biology of Reproduction 102 (6): 1170-1176 (2020). DOI: 10.1093/biolre/ioaa038
    PubMed   BOR   BOR (free access)
  • DENKER, H.-W.:
    Recent embryo twinning data prompt reconsideration of theories on a crucial role of segregation of oocyte cytoplasmic constituents in mammals.
    (Comment on: CASSER, E., WDOWIK, S., ISRAEL, S., WITTEN, A., SCHLATT, S., NORDHOFF, V., BOIANI, M.: Differences in blastomere totipotency in 2-cell mouse embryos are a maternal trait mediated by asymmetric mRNA distribution. Molec. Hum. Reproduct. 25/11, 729-744, 2019. DOI: 10.1093/molehr/gaz051)
    Molec. Hum. Reprod. 26: 193-198 (2020). DOI: 10.1093/molehr/gaaa005
    PubMed   MHR   PDF-Download AOV (214 KB)
  • DENKER, H.-W.:
    Embryonen, Embryoide, Gastruloide... Ethische Aspekte zur Selbstorganisation und zum Engineering von Stammzellkolonien und Embryonen.
    In: M. Rothhaar, M. Hähnel, R. Kipke (Eds.): Der manipulierbare Embryo. Potentialitäts- und Speziesargumente auf dem Prüfstand. Münster: Mentis (Brill), 2018, pp. 15-47. DOI: 10.30965/9783957438393_003 (Open Access)
    Mentis (Brill) (Open Access)   Google Scholar   Abstract (40 KB)   pdf-download (196 KB)
  • DENKER, H.-W.:
    Self-Organization of Stem Cell Colonies and of Early Mammalian Embryos: Recent Experiments Shed New Light on the Role of Autonomy vs. External Instructions in Basic Body Plan Development.
    Cells 5(4): E39 (2016) (Open access). DOI: 10.3390/cells5040039
    PubMed   Cells Website   pdf-download (5.16 MB)
  • DENKER, H.-W.:
    Implantation: Cell biology of embryo penetration route revisited.
    (Comment on: UCHIDA, H. et al.: How to create an embryo penetration route. Am. J. Reprod. Immunol. 75(3): 326-332, 2016. DOI: 10.1111/aji.12476)
    Am. J. Reprod. Immunol. 76(6): 429-431 (2016). DOI: 10.1111/aji.12591
    PubMed   AJRI   pdf-download (219 KB)   summary (68 KB)
  • DENKER, H.-W.:
    Comment on G. Herranz: The timing of monozygotic twinning: a criticism of the common model. Zygote (2013).
    (Comment on: HERRANZ, G.: Zygote 23(1): 27-40, 2015. DOI: 10.1017/S0967199413000257)
    Zygote 23(2): 312-314 (2015). DOI: 10.1017/S0967199413000579
    PubMed   Zygote   pdf-download (41.8 KB)
  • DENKER, H.-W.:
    A Quest for Refocussing Stem Cell Induction Strategies: How to Deal with Ethical Objections and Patenting Problems.
    In: M. Prasad and P. Di Nardo (Eds.): Innovative Strategies in Tissue Engineering. (River Publishers Series in Research and Business Chronicles: Biotechnology and Medicine; Vol. 2; A. Vertes, P. Di Nardo and P. Rameshwar, Ser.-Eds.) Aalborg, Denmark: River Publishers, 2015, pp. 117-134. DOI: 10.13052/rp-9788793237100
    Google Scholar   River Publishers   River Publishers (Open Access)   pdf-download (385 KB)
  • DENKER, H.-W.:
    Stem Cell Terminology and 'Synthetic' Embryos: A New Debate on Totipotency, Omnipotency, and Pluripotency and How It Relates to Recent Experimental Data
    Cells Tissues Organs 199: 221-227 (2014).
    PubMed   CTO Website (free access)

Recent unpublished Comments...

...on Publications (view all)

  • DENKER, H.-W.:
    Wir brauchen eine Neudefinition des Begriffs "Embryo".
    Deutsches Ärzteblatt 120 (33-34): A-1383 / B-1191 (21. August 2023).
    Deutsches Ärzteblatt   pdf-download (315 KB)
  • DENKER, H.-W.:
    Blastocyst-like cysts sprouting autonomously from stem cell cultures: Self-organization and implantation potential.
    (Comment on: KIME, C., KIYONARI, H., OHTSUKA, S., KOHBAYASHI, E., ASAHI, M., YAMANAKA, S., TAKAHASHI, M. & TOMODA, K.: Induced 2C Expression and Implantation-Competent Blastocyst-like Cysts from Primed Pluripotent Stem Cells. Stem Cell Reports 13:485-498, 2019).
    Preprint (2020). DOI: 10.13140/RG.2.2.34000.74242
    pdf-download (311 KB)
  • DENKER, H.-W.:
    „Totipotency“ of stem cells: Plasticity vs. self-organization capacity
    (Comment on: ISHIUCHI, T., ENRIQUEZ-GASCA, R., MIZUTANI, E., BOSKOVIC, A., ZIEGLER-BIRLING, C., RODRIGUEZ-TERRONES, D., WAKAYAMA, T., VAQUERIZAS, J.M., TORRES-PADILLA, M.E.: Early embryonic-like cells are induced by downregulating replication-dependent chromatin assembly. Nature Struct. Mol. Biol. 22: 662-671, 2015).
    Preprint (2015). DOI: 10.13140/RG.2.2.15761.25441
    pdf-download (113 KB)
  • DENKER, H.-W.:
    Comment on Draft NIH Guidelines for Human Stem Cell Research (2009) (Public Comment ID 16452).
    pdf-download (15.1 KB)   NIH WebsiteUnfortunately, NIH has removed this webpage.
    However, you are still welcome to download my comment as a PDF (15.1 KB).

...on Events (view all)

  • December 2012
    Stem Cell Patents: Ruling of the German Bundesgerichtshof (BGH) - a Missed Chance
    On 27 November 2012, the German Federal Court of Justice (Bundesgerichtshof, BGH) in Karlsruhe has finally ruled in the stem cell patenting case Greenpeace vs. Brüstle... [more]
  • November 2011
    Stem Cell Patents
    The European Court of Justice (ECJ) in Luxembourg ruled on October 18, 2011, that stem cells cannot be patented if their derivation involves/d sacrificing human embryos (as typical for the derivation of embryonic stem cells, ES cells)... [more]
  • April/May 2011
    Legislative initiatives concerning PID/PGD: Debates of the German Bundestag
    The German parliament (Bundestag) is presently discussing legislative initiatives for regulations of preimplantation diagnosis (PID/PGD)... [more]

...on Books (view all)

  • WEIGL, A.: Resch-Verlag (2007)
    Der preisgegebene Mensch. Überlegungen zum biotechnischen Umgang mit menschlichen Embryonen.

Recently added PDFs

  • DENKER, H.-W.:
    Formation of the blastocyst: determination of trophoblast and embryonic knot.
    Current Topics in Pathology (E. Grundmann und H.W. Kirsten, eds.) Vol. 62: Developmental Biology and Pathology (A. Gropp und K. Benirschke, Vol.-eds.). Berlin-Heidelberg-New York: Springer-Verlag, 1976, pp. 59-79.
    PubMed   SpringerLink   pdf-download (8.17 MB)   Abstract (58 KB)
  • DENKER, H.-W. and THIE, M.:
    The regulatory function of the uterine epithelium for trophoblast attachment: experimental approaches.
    In: Molecular, Cellular and Developmental Biology of Reproduction: Basic and Clinical Aspects (P.M. Motta, S.A. Nottola, G. Macchiarelli and S. Correr, Eds.).
    Italian Journal of Anatomy and Embryology 106 (2 Supplement 2): 291-306, 2001.
    pdf-download (12.2 MB) PubMed
  • DENKER, H.-W.:
    Embryonen und Embryoide: Gedanken eines Entwicklungsbiologen zu ethischen Implikationen von Autonomie und Machbarkeit.
    (Lecture) Der manipulierbare Embryo: Potentialitäts- und Speziesargumente auf dem Prüfstand (Auftakttagung zum BMBF-Projekt "Der manipulierbare Embryo"), Eichstätt, Katholische Universität Eichstätt-Ingolstadt, 3.-5. Nov. 2016.
    lecture pdf (4.70 MB)
    Continued differentiation of mammalian embryos in utero after blockage of implantation.
    Abstract No. 22, XVth EDBO International Embryological Conference, Strasbourg, 1982. DOI: 10.13140/RG.2.2.28742.91201
    abstract (376 KB)   poster (11.8 MB)

    This conference poster has now been scanned and is presented here in full length as PDF because the morphological findings that it documents have not been published in detail elsewhere. These data are of particular interest because they clearly contradict a widely held opinion that embryo implantation is an absolute prerequesite for the development of a basic body plan. This poster shows on contrast that, when hatching of rabbit embryos is prevented by proteinase inhibitor infusion into the uterus, differentiation of the embryonic anlage can continue at an only slightly reduced pace, in spite of the fact that implantation has been prevented and the embryo remains free-floating in the uterine lumen. The illustrations document in detail that basic elements of the basic body plan (like neural tube, somites) can be formed in a regular way in such non-implanted embryos.

    Shedding of the "capsule" and proteinase activity in the horse embryo.
    (Abstr.) IV Int. Sympos. on Equine Reproduction, Calgary 1986. J. Reprod. Fert. Suppl. 35, 703 (1987). DOI: 10.13140/RG.2.2.23539.96801
    pdf-download (366 KB)   poster (6.09 MB)

    This conference poster has been scanned and is presented here now in full lenghth as PDF because its photographs and data remained unique, i.e. they have not been published otherwise, and no comparable data are available in the literature. The reason is that it was not possible to continue this study on proteinases involved in horse embryo implantation, because additional specimens (of shock-frozen horse embryos within the uterus) representing the most interesting stages could not be obtained due to logistic and financial difficulties. So these data remain until today the only available details on proteolytic enzymes possibly involved in hatching of the horse embryo from its extracellular coverings/coat, the "capsule", in utero.