Engelmann Research Group
The group of Katrin Engelmann is conducting clinical and basic research. The group is internationally renowned for their expertise in the field of cell culture and cell transplantation of differentiated cells of the human eye.
Clinical research
SFM study
Corneal grafting is the only effective treatment for a number of diseases that affect the human cornea and lead to severe impairment of the visual function. The number of performed corneal transplantations has been steadily growing over the past years, however, the number of patients in need of corneal graft still exceeds by far the number of performed transplantations. In the European eye banks, the long term organ culture of donor corneas is the most widely accepted storage method, whereby the culture media used are supplemented by fetal bovine serum in concentrations ranging from 2% to 8%. Under appropriate storage conditions, the serum supplemented media allow an in vitro organ culturing of up to four weeks. The outcome of the grafting procedure is directly related to the quality of the corneal grafts after the in vitro culturing. During this period a significant decline of the corneal endothelial cell density occurs, which renders around 40% of the donor corneas unsuitable for transplantation after the period of organ culturing.
The serum supplemented culture medium has been introduced into the cornea banking more than 20 years ago and there is an obvious need for an improvement of the conditions under which the corneal grafts are cultured in. The advancements made in the fields of biosciences and biotechnology have provided cell and tissue culturing media of improved quality. The Human Endothelial SFM is a new serum free culture medium, which allows the in vitro culturing of cells and tissues to be kept under strictly defined conditions. In first experiments it could be shown that this medium provides a favourable survival rate of the corneal endothelium, which will result in a reduction of the number of grafts which are rendered unsuitable for transplantation after the period of in vitro culturing, and at the same time will provide corneal grafts with better quality.
In a DFG-sponsored clinical trial, which is serviced by the KKS Dresden, corneas cultured in this new and improved medium will be transplanted to patients that need a corneal graft. We expect that a prolongation of the period of effective organ culturing will allow a better patient management and planning, as well as an enhanced distribution of the corneal grafts between the medical centers. Furthermore, by omitting serum, the disease transfer risks associated with exposure of the recipients to corneal grafts containing undefined, potentially pathogenic serum constituents will be eliminated. Finally, the storage method will be standardized, i.e. in vitro culturing of donor corneas under strictly defined conditions, and cornea banks will be independent from the ever tightening commercial supply of FCS.
The results of this clinical trial will have an immediate impact on the process of organ culturing of donor corneas and will provide an evidence based approach for improvement of quality of care and management of patients receiving corneal grafts in eye clinics and hospitals across Germany and the European Union.
Basic research
All studies focus on optimization of culture protocols regarding maintenance of cell functions and a differentiated morphology as well as serum-free culture conditions. The overall aim of the studies is to design cell transplants for therapeutic approaches or to develop methods to induce the hidden regenerative capacity of ocular tissues.
Cornea
The group of Katrin Engelmann developed a method for cultivation and in vitro transplantation of corneal endothelial cells, a first step towards constructing corneal transplants. Previous studies led to the hypothesis of an endothelial progenitor in the corneal periphery. A monoclonal antibody directed against a human corneal endothelial-specific matrix-associated protein, an immortalised human corneal endothelial cell line and two clonally growing cell lines of human corneal endothelial cells were established and are being characterized. Current studies on corneal endothelium aim at improving the quality of corneal endothelial cells for cell transplantation. In one project we investigate the cell-matrix-interaction and engineering of transplantable cell sheets in a cooperation with the group of Carsten Werner (Institute of Polymer Research IPF Dresden). In another project we focus on transient immortalization strategies using viral gene transfer techniques in a cooperation with the group of Dirk Lindemann (Institute of Virology, TU Dresden). Functionality of the cells after cultivation on thermoresponsive substrates and after gene transfer is investigated.
The group of Engelmann is also investigating the cultivation and in vitro-transplantation of differentiated and progenitor corneal epithelial cells on amniotic membrane to constuct transplantable cell-matrix-sheets for restoration of the diseased corneal surface. Pre-treatment of amniotic membrane is a crucial aspect of these studies.
In a cooperative project with the group of Richard Funk (Institute of Anatomy, TU Dresden) we investigate immune responses after transplantation of immuno-modulated corneas in a mouse model.
Retina
The group of Engelmann developed and improved methods to culture and transplant human retinal pigment epithelial cells. Cultivation improvements such as serum-free culture protocols resulted in maintenance or re-expression of a fully differentiated morphology and functionality of the cells, e.g. polarized epithelial morphology, de novo melanogenesis, photoreceptor outer segment phagocytosis, and expression of calcium and potassium channel proteins.
Transplantation studies in a retina-degenerative animal model revealed new aspects of cellular responses after transplantation of cell suspensions. It could be shown, that suspended cells have a reduced viability and are phagocytosed by recipient macrophages after transplantation. Therefore, current studies focus on construction of transplantable cell-matrix-sheets using artificially designed collagen matrices in cooperation with the group of Daniel Müller (Biotechnological Center, TU Dresden). As with corneal endothelial cells, RPE cells will also be cultured on thermoresponsive substrates in cooperation with the group of Carsten Werner (Institute of Polymer Research IPF Dresden).
Bone Marrow stem cells
The group of Engelmann is also working on the in vitro differentiation of mesenchymal stem cells from bone marrow towards neuronal/retinal cell types in cooperation with the group of Axel Zander (Dept of Bone Marrow Transplantation, UKE Hamburg) and Richard Funk (Institute of Anatomy, TU Dresden). Transplantation of these cells into the above mentioned retina-degenerative animal model are performed in order to investigate migration and differentiation of the cells induced by tissue defects in vivo.
Selected publications
2007
Karl MO, Valtink M, Bednarz J, Engelmann K (2007) Cell Culture Conditions affect RPE Phagocytic Function. Graefe´s Arch Clin Exp Ophthalmol (Epub ahead of print, DOI 10.1007/s00417-006-0451-y)
Valtink M, Engelmann K (2007) Serum-free cultivation of adult normal human choroidal melanocytes. Graefe´s Arch Clin Exp Ophthalmol (Epub ahead of print, DOI 10.1007/s00417-007-0588-3)
2006
Nitschke M, Gramm S, Götze T, Valtink M, Drichel J, Voit B, Engelmann K, Werner C (2006) Thermo-responsive poly(NiPAAm-co-DEGMA) substrates for gentle harvest of human corneal endothelial cell sheets. J Biomed Mat Res Part A 80(4):1003-10
2005
Dannowski H, Bednarz J, Reszka R, Engelmann K, Pleyer U (2005) Lipid-mediated gene transfer of acidic fibroblast growth factor into human corneal endothelial cells. Exp Eye Res 80:93-101
Mergler S, Pleyer U, Reinach P, Bednarz J, Dannowski H, Engelmann K, Hartmann C, Yousif T (2005) EGF suppresses hydrogen peroxide induced Ca2+ influx by inhibiting L-type channel activity in cultured human corneal endothelial cells. Exp Eye Res 80:285-93
2004
Engelmann K, Bednarz J, Valtink M (2004) Prospects for endothelial transplantation. Exp Eye Res 78: 573-578
Warncke B, Valtink M, Weichel J, Engelmann K, Schäfer H (2004) Experimental rat model for therapeutic retinal pigment epithelium transplantation – unequivocal microscopical identification of human donor cells by in situ hybridisation of human-specific Alu sequences. Virchows Arch 444: 74-81
Engelmann K, Valtink M (2004) RPE cell cultivation. Graefe´s Arch Clin Exp Ophthalmol 242: 65-67
2003
Hecquet C, Lefevre G, Valtink M, Engelmann K, Mascarelli F (2003) Activation and role of MAP kinase-independent pathways in retinal pigment epithelium (RPE) cells: JNK1, P38 kinase and cell death. Invest Ophthalmol Vis Sci 44: 1320–1329
Mergler S, Dannowski H, Bednarz J, Engelmann K, Hartmann C, Pleyer U (2003) Calcium influx induced by activation of receptor tyrosine kinases in SV40-transfected human corneal endothelial cells. Exp Eye Res 77(4):485-95
2002
Weichel J, Valtink M, Richard G, Schäfer H, Engelmann K (2002) Use of an oil-hydraulic microinjection pump for subretinal infusions. Ophthalmic Surg Lasers 33: 340-342
Hecquet C, Lefevre G, Valtink M, Engelmann K, Mascarelli F (2002) Activation and role of MAP kinase-dependent pathways in retinal pigment epithelium (RPE) cells: ERK and RPE cell proliferation. Invest Ophthalmol Vis Sci 43: 3091-3098
2001
Engelmann K, Bednarz J, Schäfer HJ, Friedl P (2001) Isolation and characterization of a mouse monoclonal antibody against human corneal endothelial cells. Exp Eye Res 73: 9-16
Møller-Pedersen T, Hartmann U, Møller HJ, Ehlers N, Engelmann K (2001) Evaluation of potential organ culture media for eye banking using human donor corneas. Br J Ophthalmol 85: 1075-1079
Møller-Pedersen T, Hartmann U, Ehlers N, Engelmann K (2001) Evaluation of potential organ culture media for eye banking using a human corneal endothelial cell growth assay. Graefe's Arch Clin Exp Ophthalmol 239: 778-782
Hempel B, Bednarz J, Engelmann K (2001) Use of a serum-free medium for long-term storage of human corneas. Influence on endothelial cell density and corneal metabolism. Graefe's Arch Clin Exp Ophthalmol 239: 801-805
Hecquet C, Lefevre G, Valtink M, Engelmann K, Mascarelli F (2001) cAMP inhibits the proliferation of retinal pigmented epithelial cells through the inhibition of ERK1/2 in a PKA-independent manner. Oncogene 21: 6101-6112
2000
Bednarz J, Teifel M, Friedl P, Engelmann K (2000) Immortalization of human corneal endothelial cells (HCEC) using electroporation protocol optimized for HCEC and human retinal pigment epithelial cells. Acta Ophthalmol Scand 78: 130-136
1999
Engelmann K, Drexler D, Böhnke M (1999) Transplantation of adult human and porcine corneal endothelial cells onto human corneas in vitro. Part I: Cell culturing and transplantation procedure. Cornea 18: 199-206
Böhnke M, Eggli P, Engelmann K (1999) Transplantation of adult human and porcine corneal endothelial cells onto human corneas in vitro. Part II: Evaluation of morphology with scanning electron microscopy. Cornea 18: 207-213
Aboalchamat B, Engelmann K, Bednarz J (1999) Morphological and functional analysis of immortalized human corneal endothelial cells after transplantation. Exp Eye Res 69: 547-553
Valtink M, Engelmann K, Strauß O, Krüger R, Löliger C, Sobottka Ventura A, Richard G (1999) Physiological features of primary cultures and subcultures of human retinal epithelial cells prior to and following cryopreservation for cell transplantation. Graefe’s Arch Clin Exp Ophthalmol 237: 1001-1006
1998
Engelmann K, Sobottka Ventura A, Drexler D, Staude HJ (1998) A sensitive method for testing the quality of organ culture media of individual medium components in a cornea bank. Graefe’s Arch Clin Exp Ophthalmol 236: 312-319
Bednarz J, Rodokanaki-von Schrenck A, Engelmann K (1998) Different characteristics of endothelial cells from central and peripheral human cornea in primary culture and after sub-culture. In Vitro Cell Dev Biol 34: 149-153
1997
Bednarz J, Richard G, Böhnke M, Engelmann K (1997) Differences in proliferation and migration of corneal endothelial cells after cell transplantation in vitro. German J Ophthalmol 5: 346-351
