With a DFG Walter-Benjamin grant Dr. med. Friederike Martin will join the laboratory of Transplant Surgery Research at Harvard under the direction of Professor Stefan G. Tullius in Boston to investigate the role of biological sex for transplantation outcome.

Influences of donor and recipient sex on transplantation outcome have been described manifold, as well as an influence of sex hormones on the innate and adaptive immune response. So far, research, investigating the impact of sex hormones and different sex- and age-dependent sex-hormone levels on alloimmune response after solid organ transplantation is lacking. The aim of the project “Sex as a biological Variable in Alloimmunity” is, to delineate the impact of sex hormones and especially estrogens and age-dependent changes in estrogen-levels on alloimmune response after allogenic transplantation.  The project is based on the publication “Recipient sex and estradiol levels affect transplant outcomes in an age-specific fashion” published in the AJT in 2021 by the workgroup of Prof. Tullius.

Friederike, who already received the Sanofi Women in Transplantation fellowship grant for research in gender and sex in transplantation in 2021, will work as a Postdoc on this project in the Tullius Lab for an expected 2 years period, starting in January 2023.


Congratulations!

Priv.-Doz. Dr. Nathanael Raschzok and his team are working on strategies for (re-) conditioning of marginal liver grafts by ex vivo liver machine perfusion. The aim for the proposed job offer, which is funded by grants of the Else Kröner-Fresenius-Stiftung, is to make steatotic liver grafts, which are usually discarded from transplantation due to the high risk for the recipient, acceptable for transplantation. We have already established a small animal model of ex vivo liver machine perfusion as well as transplantation. Aim of this project is to test a clinically approved drug in dose-response studies (based on preliminary data), followed by in vivo studies in the rat liver transplantation model.

Your responsibility will be:

• Organ perfusion of murine livers in our established small animal modell for ex vivo liver machine perfusion
• Support of in rat liver transplantation experiments
• Organ recovery and transplantation (not mandatory)
• Biochemical analysis of the perfusat and the lipid metabolism (ELISA), tissue analysis (qRT-PCR, Wester Blot, immunochemistry, immunofluorescence)
• We fully support the application and submission of a doctoral thesis (e.g. Dr. rer.medic or MD/PhD)

Require­ments

• Degree in biology, biochemistry, biotechnology or medicine
• Pevious experience in molecular cell biology and/or proteinbiochemistry, or surgical research
• Proficiency in standard methods, especially histology, immunhistochemistry, qPCR, FACS, microscopy, cell culture/cell isolation
• Excellent english language skills

Personal characteristics

• innovative spirit and extraordinary motivation, interest in purposeful work
• team work orientated
• organized, ability for analytic and independent work ethic

If you're the right person: please send all application documents, e.g. cover letter, curriculum vitae, certificates, attestations, etc. to the following address, quoting the reference number by e-mail to
Charité – Universitätsmedizin Berlin
Chirurgische Klinik, Exp. Chirurgie
z.Hd. PD Dr. Nathanael Raschzok
Augustenburger Platz 1
D-13353 Berlin
nathanael.raschzok@charite.de

We have received the sad news that Professor Duška Dragun, Director of the Biomedical Innovation Academy (BIA) of the Berlin Institute of Health (BIH) and Head of the Charité BIH Clinician Scientist Program, succumbed to her long, severe, bravely endured illness on December 28, 2020 at the age of 51.
 
Her tireless efforts were devoted to her life's work: the Charité BIH Clinician Scientist Program. Ten years ago, she launched the first Clinician Scientist Program in Berlin and over the decade established and continuously expanded it as "best practice" for the German-speaking region. She has played a key role in developing and shaping the various programs for scientifically active physicians: from the Clinician Scientist Program, which enables aspiring specialists to spend up to 50 percent of their working time on research, to the Junior Clinician Scientist Program with 20 percent working time on research, which begins in the first year of specialist training, to the Advanced Clinician Scientist Program for specialists with postdoctoral qualifications. Two years ago, she successfully applied to the German Research Foundation (DFG) for the first and only Digital Clinician Scientist Program in Germany. This enables young physicians and scientists to conduct research and work in the field of digitalization in medicine and healthcare. Thus, within a few years, Duška Dragun made a significant contribution to building a new generation of young professionals for medicine – the impact of her programs will last for a long time, via promising individual careers as well as via the programmatic strengthening of a patient-oriented science.  
 
As a physician herself, Professor Duška Dragun has always been committed to research: As acting senior physician and deputy to the acting director of the Department of Nephrology and Intensive Care Medicine at the Charité Campus Virchow-Klinikum, as well as head of the nephrology research laboratory, she made highly regarded, internationally distinguished contributions to transplantation research with the goal of improving graft approach and long-term survival, preventing cardiovascular comorbidity, and thus improving the quality of life and life expectancy of transplanted patients.  She pursued her great goals with tremendous energy and passion, impressive perseverance and clear determination. She devoted her full attention to her employees, colleagues, and students, being equally attentive, understanding, and demanding.
 
The death of Duška Dragun is a great and painful loss. We will miss her greatly as director of the Charité BIH Clinician Scientist Program, as a physician, university professor and scientist. To us she was an inspiration, a mentor and an ever driving force.

Above all, however, we will greatly miss Duška as a friend.  

Acta Biomaterialia accepted our latest paper on "Engineering an endothelialized, endocrine Neo-Pancreas: evaluation of islet functionality in an ex vivo model".

Islet-based recellularization of decellularized, repurposed rat livers may form a transplantable Neo-Pancreas. The aim of this study is the establishment of the necessary protocols, the evaluation of the organ structure and the analysis of the islet functionality ex vivo.
After perfusion-based decellularization of rat livers, matrices were repopulated with endothelial cells and mesenchymal stromal cells, incubated for 8 days in a perfusion chamber and finally repopulated on day 9 with intact rodent islets. Integrity and quality of re-endothelialization was assessed by histology and FITC-dextran perfusion assay. Functionality of the islets of Langerhans was determined on day 10 and day 12 via glucose stimulated insulin secretion.
Blood gas analysis variables confirmed the stability of the perfusion cultivation. Histological staining showed that cells formed a monolayer inside the intact vascular structure. These findings were confirmed by electron microscopy. Islets infused via the bile duct could histologically be found in the parenchymal space. Adequate insulin secretion after glucose stimulation after 1-day and 3-day cultivation verified islet viability and functionality after the repopulation process.
We provide the first proof-of-concept for the functionality of islets of Langerhans engrafted in a decellularized rat liver. Furthermore, a re-endothelialization step was implemented to provide implantability. This technique can serve as a bioengineered platform to generate implantable and functional endocrine Neo-Pancreases.

Authors are Hannah Everwien, Eriselda Keshi, Karl H. Hillebrandt, Barbara Ludwig, Marie Weinhart, Peter Tang, Anika S. Beierle, Hendrik Napierala, Joseph MGV Gassner, Nicolai Seiffert, Simon Moosburner, Dominik Geisel, Anja Reutzel-Selke, Benjamin Strücker, Johann Pratschke, Nils Haep, and Igor M. Sauer.

Anna Pfefferkorn won the Best Poster prize for our work on "Molecular and cellular mechanisms of Lipocalin-2 mediated renoprotection in kidney transplantation" at the Kongress für Nephrologie 2020, held in Berlin 1.-4. October, 2020!

Lipocalin-2 (Lcn2) is distinctly upregulated in kidney transplants and serves as an early marker of AKI, DGF and acute rejection. However, the functional role and mechanisms underlying Lcn2 upregulation remain largely unknown. Using a mouse model of kidney transplantation we recently demonstrated a renoprotective role of recombinant Lcn2:Siderophore:Fe (rLcn2). However, the molecular and cellular events underlying the renoprotective effects of rLcn2 in kidney allografts remain unclear. Elucidating these events forms the primary focus of the current study.
rLcn2 significantly lowered CD8+ T cells in the allograft, LN and blood at POD 7, whereas their number remained unaffected in spleen. Nevertheless, the number of CD4+ T Lymphocytes was reduced only in lymph nodes. NKG2D+CD8+T cells and CD27+CD11b+NKp46+NK cells were the most prominent subpopulations of the cytotoxic lymphocytes whose frequencies were significantly reduced in graft, spleen and blood with the treatment of rLcn2. Besides, a significantly reduced infiltration of monocytes/macrophages was also observed at POD-7 with the said treatment. Importantly, degranulation capacity and IFNg production of intragraft and splenic CD4+ and CD8+ T cells were impaired in the treated animals. Besides, rLcn2 lowered hypoxia and reoxygenation induced cytotoxicity of the primary RTECs, associated with reduced caspase-3 cleavage and activation of Erk and AKt signaling.

rLcn2 treatments differentially affects the relative frequencies and activation of various immune cell. Besides, rLcn2 depicts cytoprotective effect on murine primary RTECs during H/R, possibly via activation of Erk and Akt signaling.

CONGRATULATIONS !

Priv.-Doz. Dr. Felix Krenzien received the Ferdinand-Sauerbruch Prize 2020 for his project and publication „The ILLS Laparoscopic Liver Surgery Fellow Skills Curriculum“ published in Annals of Surgery (online ahead of print).

Congratulations!

Laparoscopy is becoming the standard approach in liver surgery. As the degree of difficulty varies greatly from core skills to advanced procedures, strategies for teaching young surgeons need to be reconsidered. We here aimed to design a skills curriculum for LLR. Using the nominal group technique, 22 substeps of LLR were identified by 61 hepatobiliary surgeons. The raters were asked to rate (1) the difficulty of substeps and (2) the minimum number of times that the substep must be performed for mastery of the technique. According to the frequency of defined substeps, being estimated on the basis of high volume center experiences (n = 222 LLR; 1/2017-12/2018), the center's training capacity and defined goals for a 2-year fellowship were calculated.
Ten surgical substeps (45%) are routinely performed and can thus be taught sufficiently at centers carrying out ≥50 LLR in 2 years. As the mobilization of the right liver lobe and the dissection of the hepatic artery or portal vein is performed in only 27% and 28% of all LLR, respectively, sufficient training can only be provided at centers with ≥100 LLRs in 2 years. Mastery of complex parenchymal dissection (19%) and hilar lymphadenectomy (8%) can only be achieved in center performing ≥200 LLR in 2 years.
The authors suggest a stepwise approach for training of hepatobiliary fellows in LLR. Based on the estimated complexity of the substeps and the size of the center, not every substep can be learned within 2 years.

Authors are Felix Krenzien, Wenzel Schöning, Philipp Brunnbauer, Christian Benzing, Robert Öllinger, Matthias Biebl, Marcus Bahra, Nathanael Raschzok, Daniel Cherqui, David Geller, Ho-Seong Han, Go Wakabayashi, Moritz Schmelzle, Johann Pratschke, and the study group of the International Laparoscopic Liver Society (ILLS).

Biomaterials accepted our latest paper on „The Human Liver Matrisome – Proteomic Analysis of Native and Fibrotic Human Liver Extracellular Matrices for Organ Engineering Approaches“.

The production of biomaterials that endow significant morphogenic and microenvironmental cues for the constitution of cell integration and regeneration remains a key challenge in the successful implementation of functional organ replacements. Despite the vast development in the production of biological and architecturally native matrices, the complex compositions and pivotal figures by which the human matrisome mediates many of its essential functions are yet to be defined. Here we present a thorough analysis of the native human liver proteomic landscape using decellularization and defatting protocols to extract create extracellular matrix scaffolds of natural origin that can further be used in both bottom-up and top-down approaches in tissue engineering based organ replacements. Furthermore, by analyzing human liver extracellular matrices in different stages of fibrosis and cirrhosis, we have identified distinct attributes of these tissues that could potentially be exploited therapeutically and thus require further investigation. The general experimental pipeline presented in this study is applicable to any type of tissue and can be widely used for different approaches in regenerative medicine and in the construction of novel biomaterials for organ engineering approaches.

Authors are A. Daneshgar, O. Klein, G. Nebrich, M. Weinhart, P. Tang, A. Arnold, I. Ullah, J. Pohl, S. Moosburner, N. Raschzok, B. Strücker, M. Bahra, J. Pratschke, I.M. Sauer, and K.H. Hillebrandt. The authors acknowledge the support of the Cluster of Excellence Matters of Activity. Image Space Material funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany´s Excellence Strategy – EXC 2025.