@phdthesis{Berberich2024, author = {Berberich, Oliver}, title = {Lateral Cartilage Tissue Integration - Evaluation of Bonding Strength and Tissue Integration \(in\) \(vitro\) Utilizing Biomaterials and Adhesives}, doi = {10.25972/OPUS-34602}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-346028}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Articular cartilage defects represent one of the most challenging clinical problem for orthopedic surgeons and cartilage damage after trauma can result in debilitating joint pain, functional impairment and in the long-term development of osteoarthritis. The lateral cartilage-cartilage integration is crucial for the long-term success and to prevent further tissue degeneration. Tissue adhesives and sealants are becoming increasingly more popular and can be a beneficial approach in fostering tissue integration, particularly in tissues like cartilage where alternative techniques, such as suturing, would instead introduce further damage. However, adhesive materials still require optimization regarding the maximization of adhesion strength on the one hand and long-term tissue integration on the other hand. In vitro models can be a valuable support in the investigation of potential candidates and their functional mechanisms. For the conducted experiments within this work, an in vitro disc/ring model obtained from porcine articular cartilage tissue was established. In addition to qualitative evaluation of regeneration, this model facilitates the implementation of biomechanical tests to quantify cartilage integration strength. Construct harvesting for histology and other evaluation methods could be standardized and is ethically less questionable compared to in vivo testing. The opportunity of cell culture technique application for the in vitro model allowed a better understanding of cartilage integration processes. Tissue bonding requires chemical or physical interaction of the adhesive material and the substrate. Adhesive hydrogels can bind to the defect interface and simultaneously fill the gap of irregularly shaped defect voids. Fibrin gels are derived from the physiological blood-clot formation and are clinically applied for wound closure. Within this work, comparisons of different fibrin glue formulations with the commercial BioGlue® were assessed, which highlighted the need for good biocompatibility when applied on cartilage tissue in order to achieve satisfying long-term integration. Fibrin gel formulations can be adapted with regard to their long-term stability and when applied on cartilage disc/ring constructs improved integrative repair is observable. The kinetic of repairing processes was investigated in fibrin-treated cartilage composites as part of this work. After three days in vitro cultivation, deposited extracellular matrix (ECM) was obvious at the glued interface that increased further over time. Interfacial cell invasion from the surrounding native cartilage was detected from day ten of tissue culture. The ECM formation relies on molecular factors, e.g., as was shown representatively for ascorbic acid, and contributes to increasing integration strengths over time. The experiments performed with fibrin revealed that the treatment with a biocompatible adhesive that allows cartilage neosynthesis favors lateral cartilage integration in the long term. However, fibrin has limited immediate bonding strength, which is disadvantageous for use on articular cartilage that is subject to high mechanical stress. The continuing aim of this thesis was to further develop adhesive mechanisms and new adhesive hydrogels that retain the positive properties of fibrin but have an increased immediate bonding strength. Two different photochemical approaches with the advantage of on-demand bonding were tested. Such treatment potentially eases the application for the professional user. First, an UV light induced crosslinking mechanism was transferred to fibrin glue to provide additional bonding strength. For this, the cartilage surface was functionalized with highly reactive light-sensitive diazirine groups, which allowed additional covalent bonds to the fibrin matrix and thus increased the adhesive strength. However, the disadvantages of this approach were the multi-step bonding reactions, the need for enzymatic pretreatment of the cartilage, expensive reagents, potential UV-light damage, and potential toxicity hazards. Due to the mentioned disadvantages, no further experiments, including long-term culture, were carried out. A second photosensitive approach focused on blue light induced crosslinking of fibrinogen (RuFib) via a photoinitiator molecule instead of using thrombin as a crosslinking mediator like in normal fibrin glue. The used ruthenium complex allowed inter- and intramolecular dityrosine binding of fibrinogen molecules. The advantage of this method is a one-step curing of fibrinogen via visible light that further achieved higher adhesive strengths than fibrin. In contrast to diazirine functionalization of cartilage, the ruthenium complex is of less toxicological concern. However, after in vitro cultivation of the disc/ring constructs, there was a decrease in integration strength. Compared to fibrin, a reduced cartilage synthesis was observed at the defect. It is also disadvantageous that a direct adjustment of the adhesive can only be made via protein concentration, since fibrinogen is a natural protein that has a fixed number of tyrosine binding sites without chemical modification. An additional cartilage adhesive was developed that is based on a mussel-inspired adhesive mechanism in which reactivity to a variety of substrates is enabled via free DOPA amino acids. DOPA-based adhesion is known to function in moist environments, a major advantage for application on water-rich cartilage tissue surrounded by synovial liquid. Reactive DOPA groups were synthetically attached to a polymer, here POx, to allow easy chemical modifiability, e.g. insertion of hydrolyzable ester motifs for tunable degradation. The possibility of preparing an adhesive hybrid hydrogel of POx in combination with fibrinogen led to good cell compatibility as was similarly observed with fibrin, but with increased immediate adhesive strength. Degradation could be adjusted by the amount of ester linkages on the POx and a direct influence of degradation rates on the development of integration in the in vitro model could be shown. Hydrogels are well suited to fill defect gaps and immediate integration can be achieved via adhesive properties. The results obtained show that for the success of long-term integration, a good ability of the adhesive to take up synthesized ECM components and cells to enable regeneration is required. The degradation kinetics of the adhesive must match the remodeling process to avoid intermediate loss of integration power and to allow long-term firm adhesion to the native tissue. Hydrogels are not only important as adhesives for smaller lesions, but also for filling large defect volumes and populating them with cells to produce tissue engineered cartilage. Many different hydrogel types suitable for cartilage synthesis are reported in the literature. A long-term stable fibrin formulation was tested in this work not only as an adhesive but also as a bulk hydrogel construct. Agarose is also a material widely used in cartilage tissue engineering that has shown good cartilage neosynthesis and was included in integration assessment. In addition, a synthetic hyaluronic acid-based hydrogel (HA SH/P(AGE/G)) was used. The disc/ring construct was adapted for such experiments and the inner lumen of the cartilage ring was filled with the respective hydrogel. In contrast to agarose, fibrin and HA-SH/P(AGE/G) gels have a crosslink mechanism that led to immediate bonding upon contact with cartilage during curing. The enhanced cartilage neosynthesis in agarose compared to the other hydrogel types resulted in improved integration during in vitro culture. This shows that for the long-term success of a treatment, remodeling of the hydrogel into functional cartilage tissue is a very high priority. In order to successfully treat larger cartilage defects with hydrogels, new materials with these properties in combination with chemical modifiability and a direct adhesion mechanism are one of the most promising approaches.}, subject = {Knorpel}, language = {en} } @phdthesis{PenaMosca2024, author = {Pe{\~n}a Mosca, Mar{\´i}a Josefina}, title = {Local regulation of T-cell immunity in the intestinal mucosa}, doi = {10.25972/OPUS-35266}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-352665}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {After priming in Peyer's patches (PPs) and mesenteric lymph nodes (mLN) T- cells infiltrate the intestine through lymphatic draining and homing through the bloodstream. However, we found that in mouse models of acute graft-versus-host disease (GvHD), a subset of alloreactive T-cells directly migrates from PPs to the adjacent intestinal lamina propria (LP), bypassing the normal lymphatic drainage and vascular trafficking routes. Notably, this direct migration occurred in irradiated and unirradiated GvHD models, indicating that irradiation is not a prerequisite for this observed behavior. Next, we established a method termed serial intravascular staining (SIVS) in mouse models to systematically investigate the trafficking and migration of donor T- cells in the early stages of acute GvHD initiation. We found that the direct migration of T-cells from PPs to LP resulted in faster recruitment of cells after allogeneic hematopoietic cell transplantation (allo-HCT). These directly migrating T-cells were found to be in an activated and proliferative state, exhibiting a TH1/TH17-like phenotype and producing cytokines such as IFN-γ and TNF-α. Furthermore, we observed that the directly migrating alloreactive T-cells expressed specific integrins (α4+, αE+) and chemokine receptors (CxCR3+, CCR5+, and CCR9+). Surprisingly, blocking these integrins and chemokine-coupled receptors did not hinder the direct migration of T- cells from PPs to LP, suggesting the involvement of alternative mechanisms. Previous experiments ruled out the involvement of S1PR1 and topographical features of macrophages, leading us to hypothesize that mediators of cytoskeleton reorganization, such as Coro1a, Dock2, or Cdc42, may play a role in this unique migration process. Additionally, we observed that directly migrating T-cells created a local inflammatory microenvironment, which attracts circulating T-cells. Histological analysis confirmed that alloreactive PPs-derived T-cells and bloodborne T-cells colocalized. We employed two experimental approaches, including either photoconversion of T-cells in PPs or direct transfer of activated T-cells into the vasculature, to demonstrate this colocalization. We hypothesize that cytokines released by migrating T-cells, such as IFN-γ and TNF-α, may play a role in recruiting T-cells from the vasculature, as inhibiting chemokine-coupled receptors did not impair recruitment.}, subject = {T-Lymphozyt}, language = {en} } @phdthesis{Laesker2023, author = {L{\"a}sker, Katharina}, title = {The influence of the short-chain fatty acid butyrate on "Signal transducer and activator of transcription 3" (STAT3) and selected inflammatory genes in the colon carcinoma cell line CACO-2 cultured in 2D and 3D}, doi = {10.25972/OPUS-30038}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300389}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2023}, abstract = {A disturbance in the symbiotic mutualism between the intestinal microbiome and the human host's organism (syn. dysbiosis) accompanies the development of a variety of inflammatory and metabolic diseases that comprise the Metabolic Syndrome, chronic inflammatory gut diseases like Crohn's disease, Non-alcoholic fatty liver disease (NAFLD) and cardiovascular diseases, among others. The changed uptake and effectiveness of short chain fatty acids (SCFAs) as well as an increase of the intestinal permeability are common, interdependent disease elements in this regard. Short chain fatty acids are end-products of intestinal bacterial fermentation and affect the mucosal barrier integrity via numerous molecular mechanisms. There is evidence to suggest, that SCFAs have a modulating influence on Signal transducer and activator of transcription 3 (STAT3) in intestinal epithelial cells. STAT3 is a central gene-transcription factor in signaling pathways of proliferation and inflammation. It can be activated by growth factors and other intercellular signaling molecules like the cytokine Oncostatin M (OSM). The mode of STAT3's activation exhibits, finally, a decisive influence on the immunological balance at the intestinal mucosa. Therefore, the posttranslational modification of STAT3 under the influence of SCFAs is likely to be a very important factor within the development and -progression of dysbiosis-associated diseases. In this study, a clear positive in vitro-effect of the short chain fatty acid butyrate on the posttranslational serine727-phosphorylation of STAT3 and its total protein amount in the human adenocarcinoma cell line CACO2 is verified. Moreover, an increased gene expression of the OSM-receptor subunit OSMRβ can be observed after butyrate incubation. Histone deacetylase inhibition is shown to have a predominant role in these effects. Furthermore, a subsequent p38 MAPK-activation by Butyrate is found to be a key molecular mechanism regarding the STAT3-phosphorylation at serine727-residues. To consider the portion of butyrate receptor signaling in this context in future assays, a CACO-2 cell 3D-culture model is introduced in which an improvement of the GPR109A-receptor expression in CACO-2 cells is accomplished.}, subject = {Butyrate }, language = {en} } @article{SolimandoBittrichShahinietal.2023, author = {Solimando, Antonio G. and Bittrich, Max and Shahini, Endrit and Albanese, Federica and Fritz, Georg and Krebs, Markus}, title = {Determinants of COVID-19 disease severity - lessons from primary and secondary immune disorders including cancer}, series = {International Journal of Molecular Sciences}, volume = {24}, journal = {International Journal of Molecular Sciences}, number = {10}, issn = {1422-0067}, doi = {10.3390/ijms24108746}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-319412}, year = {2023}, abstract = {At the beginning of the COVID-19 pandemic, patients with primary and secondary immune disorders — including patients suffering from cancer — were generally regarded as a high-risk population in terms of COVID-19 disease severity and mortality. By now, scientific evidence indicates that there is substantial heterogeneity regarding the vulnerability towards COVID-19 in patients with immune disorders. In this review, we aimed to summarize the current knowledge about the effect of coexistent immune disorders on COVID-19 disease severity and vaccination response. In this context, we also regarded cancer as a secondary immune disorder. While patients with hematological malignancies displayed lower seroconversion rates after vaccination in some studies, a majority of cancer patients' risk factors for severe COVID-19 disease were either inherent (such as metastatic or progressive disease) or comparable to the general population (age, male gender and comorbidities such as kidney or liver disease). A deeper understanding is needed to better define patient subgroups at a higher risk for severe COVID-19 disease courses. At the same time, immune disorders as functional disease models offer further insights into the role of specific immune cells and cytokines when orchestrating the immune response towards SARS-CoV-2 infection. Longitudinal serological studies are urgently needed to determine the extent and the duration of SARS-CoV-2 immunity in the general population, as well as immune-compromised and oncological patients.}, language = {en} } @article{LuuSchuetzLauthetal.2023, author = {Luu, Maik and Sch{\"u}tz, Burkhard and Lauth, Matthias and Visekruna, Alexander}, title = {The impact of gut microbiota-derived metabolites on the tumor immune microenvironment}, series = {Cancers}, volume = {15}, journal = {Cancers}, number = {5}, issn = {2072-6694}, doi = {10.3390/cancers15051588}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-311005}, year = {2023}, abstract = {Prevention of the effectiveness of anti-tumor immune responses is one of the canonical cancer hallmarks. The competition for crucial nutrients within the tumor microenvironment (TME) between cancer cells and immune cells creates a complex interplay characterized by metabolic deprivation. Extensive efforts have recently been made to understand better the dynamic interactions between cancer cells and surrounding immune cells. Paradoxically, both cancer cells and activated T cells are metabolically dependent on glycolysis, even in the presence of oxygen, a metabolic process known as the Warburg effect. The intestinal microbial community delivers various types of small molecules that can potentially augment the functional capabilities of the host immune system. Currently, several studies are trying to explore the complex functional relationship between the metabolites secreted by the human microbiome and anti-tumor immunity. Recently, it has been shown that a diverse array of commensal bacteria synthetizes bioactive molecules that enhance the efficacy of cancer immunotherapy, including immune checkpoint inhibitor (ICI) treatment and adoptive cell therapy with chimeric antigen receptor (CAR) T cells. In this review, we highlight the importance of commensal bacteria, particularly of the gut microbiota-derived metabolites that are capable of shaping metabolic, transcriptional and epigenetic processes within the TME in a therapeutically meaningful way.}, language = {en} } @article{StephanTascilarYalcinMutluetal.2023, author = {Stephan, Marlene and Tascilar, Koray and Yalcin-Mutlu, Melek and Hagen, Melanie and Haschka, Judith and Reiser, Michaela and Hartmann, Fabian and Kleyer, Arnd and Hueber, Axel J. and Manger, Bernhard and Figueiredo, Camille and Cobra, Jayme Fogagnolo and Tony, Hans-Peter and Finzel, Stephanie and Kleinert, Stefan and Wendler, J{\"o}rg and Schuch, Florian and Ronneberger, Monika and Feuchtenberger, Martin and Fleck, Martin and Manger, Karin and Ochs, Wolfgang and Schmitt-Haendle, Matthias and Lorenz, Hannes Martin and N{\"u}sslein, Hubert and Alten, Rieke and Henes, Joerg and Kr{\"u}ger, Klaus and Schett, Georg and Rech, J{\"u}rgen}, title = {Physical function of RA patients tapering treatment — a post hoc analysis of the randomized controlled RETRO trial}, series = {Journal of Clinical Medicine}, volume = {12}, journal = {Journal of Clinical Medicine}, number = {11}, issn = {2077-0383}, doi = {10.3390/jcm12113723}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-319349}, year = {2023}, abstract = {Several studies have shown that tapering or stopping disease-modifying anti-rheumatic drugs (DMARDs) in rheumatoid arthritis (RA) patients in sustained remission is feasible. However, tapering/stopping bears the risk of decline in physical function as some patients may relapse and face increased disease activity. Here, we analyzed the impact of tapering or stopping DMARD treatment on the physical function of RA patients. The study was a post hoc analysis of physical functional worsening for 282 patients with RA in sustained remission tapering and stopping DMARD treatment in the prospective randomized RETRO study. HAQ and DAS-28 scores were determined in baseline samples of patients continuing DMARD (arm 1), tapering their dose by 50\% (arm 2), or stopping after tapering (arm 3). Patients were followed over 1 year, and HAQ and DAS-28 scores were evaluated every 3 months. The effect of treatment reduction strategy on functional worsening was assessed in a recurrent-event Cox regression model with a study-group (control, taper, and taper/stop) as the predictor. Two-hundred and eighty-two patients were analyzed. In 58 patients, functional worsening was observed. The incidences suggest a higher probability of functional worsening in patients tapering and/or stopping DMARDs, which is likely due to higher relapse rates in these individuals. At the end of the study, however, functional worsening was similar among the groups. Point estimates and survival curves show that the decline in functionality according to HAQ after tapering or discontinuation of DMARDs in RA patients with stable remission is associated with recurrence, but not with an overall functional decline.}, language = {en} } @article{SudarevicTroyaFuchsetal.2023, author = {Sudarevic, Boban and Troya, Joel and Fuchs, Karl-Hermann and Hann, Alexander and Vereczkei, Andras and Meining, Alexander}, title = {Design and development of a flexible 3D-printed endoscopic grasping instrument}, series = {Applied Sciences}, volume = {13}, journal = {Applied Sciences}, number = {9}, issn = {2076-3417}, doi = {10.3390/app13095656}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-319186}, year = {2023}, abstract = {(1) Background: Interventional endoscopic procedures are growing more popular, requiring innovative instruments and novel techniques. Three-dimensional printing has demonstrated great potential for the rapid development of prototypes that can be used for the early assessment of various concepts. In this work, we present the development of a flexible endoscopic instrument and explore its potential benefits. (2) Methods: The properties of the instrument, such as its maneuverability, flexibility, and bending force, were evaluated in a series of bench tests. Additionally, the effectiveness of the instrument was evaluated in an ex vivo porcine model by medical experts, who graded its properties and performance. Furthermore, the time necessary to complete various interventional endoscopic tasks was recorded. (3) Results: The instrument achieved bending angles of ±216° while achieving a bending force of 7.85 (±0.53) Newtons. The time needed to reach the operating region was 120 s median, while it took 70 s median to insert an object in a cavity. Furthermore, it took 220 s median to insert the instrument and remove an object from the cavity. (4) Conclusions: This study presents the development of a flexible endoscopic instrument using three-dimensional printing technology and its evaluation. The instrument demonstrated high bending angles and forces, and superior properties compared to the current state of the art. Furthermore, it was able to complete various interventional endoscopic tasks in minimal time, thus potentially leading to the improved safety and effectiveness of interventional endoscopic procedures in the future.}, language = {en} } @article{GelbrichMorbachDeutschbeinetal.2023, author = {Gelbrich, G{\"o}tz and Morbach, Caroline and Deutschbein, Timo and Fassnacht, Martin and St{\"o}rk, Stefan and Heuschmann, Peter U.}, title = {The population comparison index: an intuitive measure to calibrate the extent of impairments in patient cohorts in relation to healthy and diseased populations}, series = {International Journal of Environmental Research and Public Health}, volume = {20}, journal = {International Journal of Environmental Research and Public Health}, number = {3}, issn = {1660-4601}, doi = {10.3390/ijerph20032168}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-304933}, year = {2023}, abstract = {We assume that a specific health constraint, e.g., a certain aspect of bodily function or quality of life that is measured by a variable X, is absent (or irrelevant) in a healthy reference population (Ref0), and it is materially present and precisely measured in a diseased reference population (Ref1). We further assume that some amount of this constraint of interest is suspected to be present in a population under study (SP). In order to quantify this issue, we propose the introduction of an intuitive measure, the population comparison index (PCI), that relates the mean value of X in population SP to the mean values of X in populations Ref0 and Ref1. This measure is defined as PCI[X] = (mean[X|SP] - mean[X|Ref0])/(mean[X|Ref1] - mean[X|Ref0]) × 100[\%], where mean[X|.] is the average value of X in the respective group of individuals. For interpretation, PCI[X] ≈ 0 indicates that the values of X in the population SP are similar to those in population Ref0, and hence, the impairment measured by X is not materially present in the individuals in population SP. On the other hand, PCI[X] ≈ 100 means that the individuals in SP exhibit values of X comparable to those occurring in Ref1, i.e., the constraint of interest is equally present in populations SP and Ref1. A value of 0 < PCI[X] < 100 indicates that a certain percentage of the constraint is present in SP, and it is more than in Ref0 but less than in Ref1. A value of PCI[X] > 100 means that population SP is even more affected by the constraint than population Ref1.}, language = {en} } @article{MeierMoebusHeigletal.2023, author = {Meier, Johannes P. and M{\"o}bus, Selina and Heigl, Florian and Asbach-Nitzsche, Alexandra and Niller, Hans Helmut and Plentz, Annelie and Avsar, Korkut and Heiß-Neumann, Marion and Schaaf, Bernhard and Cassens, Uwe and Seese, Bernd and Teschner, Daniel and Handzhiev, Sabin and Graf, Uwe and L{\"u}bbert, Christoph and Steinmaurer, Monika and Kontogianni, Konstantina and Berg, Christoph and Maieron, Andreas and Blaas, Stefan H. and Wagner, Ralf and Deml, Ludwig and Barabas, Sascha}, title = {Performance of T-Track\(^®\) TB, a novel dual marker RT-qPCR-based whole-blood test for improved detection of active tuberculosis}, series = {Diagnostics}, volume = {13}, journal = {Diagnostics}, number = {4}, issn = {2075-4418}, doi = {10.3390/diagnostics13040758}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-304113}, year = {2023}, abstract = {Tuberculosis (TB) is one of the leading causes of death by an infectious disease. It remains a major health burden worldwide, in part due to misdiagnosis. Therefore, improved diagnostic tests allowing the faster and more reliable diagnosis of patients with active TB are urgently needed. This prospective study examined the performance of the new molecular whole-blood test T-Track\(^®\) TB, which relies on the combined evaluation of IFNG and CXCL10 mRNA levels, and compared it to that of the QuantiFERON\(^®\)-TB Gold Plus (QFT-Plus) enzyme-linked immunosorbent assay (ELISA). Diagnostic accuracy and agreement analyses were conducted on the whole blood of 181 active TB patients and 163 non-TB controls. T-Track\(^®\) TB presented sensitivity of 94.9\% and specificity of 93.8\% for the detection of active TB vs. non-TB controls. In comparison, the QFT-Plus ELISA showed sensitivity of 84.3\%. The sensitivity of T-Track\(^®\) TB was significantly higher (p < 0.001) than that of QFT-Plus. The overall agreement of T-Track\(^®\) TB with QFT-Plus to diagnose active TB was 87.9\%. Out of 21 samples with discordant results, 19 were correctly classified by T-Track\(^®\) TB while misclassified by QFT-Plus (T-Track\(^®\) TB-positive/QFT-Plus-negative), and two samples were misclassified by T-Track\(^®\) TB while correctly classified by QFT-Plus (T-Track\(^®\) TB-negative/QFT-Plus-positive). Our results demonstrate the excellent performance of the T-Track\(^®\) TB molecular assay and its suitability to accurately detect TB infection and discriminate active TB patients from non-infected controls.}, language = {en} } @article{HaertleBuenacheCuestaHernandezetal.2023, author = {Haertle, Larissa and Buenache, Natalia and Cuesta Hern{\´a}ndez, Hip{\´o}lito Nicol{\´a}s and Simicek, Michal and Snaurova, Renata and Rapado, Inmaculada and Martinez, Nerea and L{\´o}pez-Mu{\~n}oz, Nieves and S{\´a}nchez-Pina, Jos{\´e} Mar{\´i}a and Munawar, Umair and Han, Seungbin and Ruiz-Heredia, Yanira and Colmenares, Rafael and Gallardo, Miguel and Sanchez-Beato, Margarita and Piris, Miguel Angel and Samur, Mehmet Kemal and Munshi, Nikhil C. and Ayala, Rosa and Kort{\"u}m, Klaus Martin and Barrio, Santiago and Mart{\´i}nez-L{\´o}pez, Joaqu{\´i}n}, title = {Genetic alterations in members of the proteasome 26S subunit, AAA-ATPase (PSMC) gene family in the light of proteasome inhibitor resistance in multiple myeloma}, series = {Cancers}, volume = {15}, journal = {Cancers}, number = {2}, issn = {2072-6694}, doi = {10.3390/cancers15020532}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-305013}, year = {2023}, abstract = {For the treatment of Multiple Myeloma, proteasome inhibitors are highly efficient and widely used, but resistance is a major obstacle to successful therapy. Several underlying mechanisms have been proposed but were only reported for a minority of resistant patients. The proteasome is a large and complex machinery. Here, we focus on the AAA ATPases of the 19S proteasome regulator (PSMC1-6) and their implication in PI resistance. As an example of cancer evolution and the acquisition of resistance, we conducted an in-depth analysis of an index patient by applying FISH, WES, and immunoglobulin-rearrangement sequencing in serial samples, starting from MGUS to newly diagnosed Multiple Myeloma to a PI-resistant relapse. The WES analysis uncovered an acquired PSMC2 Y429S mutation at the relapse after intensive bortezomib-containing therapy, which was functionally confirmed to mediate PI resistance. A meta-analysis comprising 1499 newly diagnosed and 447 progressed patients revealed a total of 36 SNVs over all six PSMC genes that were structurally accumulated in regulatory sites for activity such as the ADP/ATP binding pocket. Other alterations impact the interaction between different PSMC subunits or the intrinsic conformation of an individual subunit, consequently affecting the folding and function of the complex. Interestingly, several mutations were clustered in the central channel of the ATPase ring, where the unfolded substrates enter the 20S core. Our results indicate that PSMC SNVs play a role in PI resistance in MM.}, language = {en} }