Refine
Year of publication
Document Type
- Article (5419)
- Doctoral Thesis (1530)
- Part of Periodical (211)
- Conference Proceeding (196)
- Preprint (176)
- Book (86)
- Contribution to a Periodical (69)
- Review (51)
- Working Paper (22)
- Part of a Book (17)
Language
Has Fulltext
- yes (7789) (remove)
Is part of the Bibliography
- no (7789) (remove)
Keywords
- inflammation (84)
- COVID-19 (62)
- SARS-CoV-2 (49)
- apoptosis (40)
- Inflammation (38)
- cancer (38)
- glioblastoma (38)
- breast cancer (34)
- prostate cancer (30)
- autophagy (29)
Institute
- Medizin (7789) (remove)
Im Fokus der vorliegenden Arbeit stand die Fragestellung, inwieweit ORF10 von B. recurrentis, dem Erreger des Läuserückfallfiebers, mit verschiedenen Komplementkomponenten interagieren kann.
Mit funktionellen Komplementtests konnte gezeigt werden, dass ORF10 den klassischen, den alternativen sowie den Lektin-Weg inhibiert, wobei sich die stärkste Inhibition gegenüber dem alternativen Weg manifestierte. Darüber hinaus ließ sich in einem Zell-basierten Hämolyse-Assay eine Inhibition des terminalen Komplementweges durch ORF10 nachweisen.
Die durchgeführten Bindungsanalysen mit verschiedenen Komplementkomponenten führten zu dem Ergebnis, dass ORF10 mit C1q, C1s, C3, C3b, C4b und C5 interagiert und diese Protein-Protein-Interaktion mit den Komplementkomponenten C1q, C3, C3b und C4b durch einen dosisabhängigen Verlauf charakterisiert ist. Eine Bindung von C1r, C2, C4, FB, FH sowie FI konnte jedoch nicht nachgewiesen werden.
Auf Basis der modellierten Struktur von ORF10 wurden mithilfe der In-vitro-Mutagenese drei verschiedene Varianten generiert, die jedoch nicht affinitätschromatographisch aus E. coli-Zelllysaten isoliert werden konnten und deshalb nicht für weiterführende funktionelle Analysen zur Verfügung standen.
Die Ergebnisse der Serumbakterizidie-Tests mit einem „gain of function“-Borrelienstamm, welcher ORF10 heterolog produzieren sollte, ergaben, dass keine erhöhte Resistenz gegenüber Humanserum nachgewiesen werden konnte. Inwieweit ORF10 bei der intrinsischen Serumresistenz von B. recurrentis beteiligt ist, lässt sich abschließend nicht vollumfänglich erklären.
Background: Survival data regarding cytoreductive nephrectomy (CN) in metastatic renal cell carcinoma (mRCC) patients according to the type and extent of tumor-associated vascular thrombus are scarce.
Objective: To test for survival differences in mRCC patients treated with CN according to the type and extent of tumor-associated vascular thrombus.
Design, setting, and participants: Within Surveillance, Epidemiology, and End Results Research Plus (2004–2017), we identified CN mRCC patients with renal vein (pT3a-TT) versus infradiaphragmatic inferior vena cava (IVC; pT3b) versus supradiaphragmatic IVC tumor thrombus/IVC invasion (pT3c).
Outcome measurements and statistical analysis: Overall survival (OS) was addressed in Kaplan-Meier and Cox regression analyses, in addition to 3-mo landmark analyses.
Results and limitations: Of 2170 mRCC patients, 1880 (87%), 204 (9%), and 86 (4%) harbored pT3a-TT, pT3b, and pT3c, respectively. The respective median OS periods were 21, 23, and 12 mo (p < 0.001). In multivariable Cox regression models, pT3c stage, but not pT3b stage, was an independent predictor of higher overall mortality (hazard ratio [HR]: 1.37; 95% confidence interval [CI]: 1.09–1.73; p = 0.007), as well as in 6-mo landmark analyses (HR: 1.36; 95% CI: 1.02–1.80; p = 0.04). In the sensitivity analysis, relying on all pT3a patients, the predictor status of pT3c stage remained unchanged (HR: 1.37; 95% CI: 1.09–1.71; p = 0.007). Limitations have to be addressed regarding the sample size and the retrospective design of the current study.
Conclusions: Although overall mortality is significantly higher in pT3c mRCC patients than in their pT3b and pT3a-TT counterparts, these individuals may still expect 12-mo or better OS after CN versus virtually 2-yr OS in their pT3a and pT3b counterparts.
Patient summary: In this study, we looked at the survival outcomes of metastatic renal cell carcinoma patients who presented with tumor thrombus at cytoreductive nephrectomy. Even though these patients with most advanced tumor thrombus stage demonstrated lower survival rates, the median overall survival was still 1 yr.
Middle-aged persons with multimorbidity have to take their illnesses into account in their daily work, family and leisure activities. The MuMiA project aims to identify early preventive measures that make it easier for those between 30 and 60 years of age with multiple chronic diseases to manage their illnesses in their everyday lives. An interdisciplinary workshop and interviews with multimorbid middle-aged adults and their principal healthcare providers will be used to collect information on the management of care in the contexts of patients’ daily work, family and leisure activities. Data obtained in the interviews will be coded inductively and analysed using content analysis. Workshop outputs will be transcribed and evaluated by the authors. This study has received ethical approval from the Faculty of Medicine Ethics Committee of Goethe University (2021-47). The project will generate prevention recommendations that reflect the experiences of middle-aged persons living with multimorbidity and the views of their principal healthcare providers. The findings will be disseminated via conferences and peer-reviewed publications.
Development of a multidimensional pain questionnaire in professional dance (MPQDA): a pilot study
(2022)
Background: Pain is part of the everyday life of professional dancers. It can indicate health risks and impair the ability to work. Suitable screening tools can be used to identify pain and its risk potential. A comprehensive, multidimensional, differentiated assessment tool for pain in professional dance does not currently exist.
Methods: An initial questionnaire was developed in German and English and was assessed in a qualitative pretest. In a field study with a cross-sectional design including n = 72 dancers from Germany (n = 36 responses each in the English and German language versions), the questionnaire was optimized by item analysis, its psychometric properties (dimensionality, construct validity, reliability) were examined and the ability of the pain dimensions to classify the subjective ability to work in training was analyzed (ROC analysis).
Results: The developed Multidimensional Pain Questionnaire in Professional Dance (MPQDA) was reduced and optimized in its psychometric properties. Following questions were reduced in their items or answer categories: pain localizations (from 20 to 15 regions), accompanying symptoms (from 6 to 3 items), sensory and affective pain quality (from 20 to 10 items), pain frequency (from 4 to 3 answer categories), and the motives of working with pain (from 14 to 12 items). Regarding the subjective ability to work in training, the variables of the ability to work in rehearsals and in performances, as well as the accompanying symptoms of tension and mobility restrictions, showed a relatively good classification ability (Area under the Curve (AUC) ≥ 0.7 in the 95% confidence interval) and significant, moderate to strong correlations (Somers' D > 0.25, p < 0.05). The classification ability of the other pain dimensions was largely absent or poor.
Conclusion: The MPQDA differentiates various pain dimensions in professional dancers and is available in a compatible manner in German and English. The clinical relevance needs to be explored further in the future.
Up to the present, there has been a lack of studies on the skin health of professional and recreational dancers. Dancers are at risk of skin diseases due to contact with allergenic or irritating substances and working in humid environments. The aim of the present study was, therefore, to examine skin health in two different dance styles and training periods. Methods: Physical dermatological examination of professional dancers (PD; n = 35) and Latin American formation dancers (LD; n = 79) after a 4-week period of recovery (T0) and a period of high training or work load (T1). Results: PD are significantly more frequently affected by skin dermatoses than LD (T0, p = 0.004) (frontal traction alopecia, hair loss, facial seborrhoea, xerosis cutis of the trunk and extremities, and facial folliculitis). The following significant differences between the sexes were observed in the LD: more folliculitis of the trunk in male subjects (T0 and T1, p = 0.009), more frequent xerosis cutis of the extremities (p < 0.001) and perioral dermatitis in female subjects (T1, p = 0.043). Subjects with skin lesions trained more frequently, performed more times per year, and had longer dance experience. Discussion: Based on the findings, preventive measures for skin protection (especially informing dancers about skin health) are necessary. At the same time, further studies on this topic are important.
The deep fascia is intimately linked to skeletal muscle and may be involved in delayed onset muscle soreness (DOMS). The present study therefore explored the effect of eccentric exercise on fascia stiffness and its relation with DOMS. Healthy active male adults (n = 19, 27 ± 4 years) performed 6 x 10 maximal eccentric knee flexions using an isokinetic dynamometer. Before (baseline) as well as immediately (T0), 1 hour (T1), and each day up to 72 hours (T24 to T72) afterwards, shear wave elastography was used to measure the mechanical stiffness of the biceps femoris muscle and the overlying fascia. As a surrogate of DOMS, pain upon palpation was captured by means of a 100mm visual analogue scale. While muscle stiffness remained unchanged (p > 0.05), deep fascia stiffness increased from baseline to T24 (median: 18 kPa to 21.12 kPa, p = 0.017) and T72 (median: 18 kPa to 21.3 kPa, p = 0.001) post-exercise. Linear regression showed an association of stiffness changes at T24 and pressure pain at T72 (r2 = 0.22, p < 0.05). Maximal eccentric exercise leads to a stiffening of the fascia, which, in turn, is related to the magnitude of future DOMS. Upcoming research should therefore gauge the effectiveness of interventions modifying the mechanical properties of the connective tissue in order to accelerate recovery.
Background: Primary viral myocarditis associated with severe acute respiratory syndrome coronavirus 2 (SARS-Cov2) infection is a rare diagnosis.
Case presentation: We report the case of an unvaccinated, healthy patient with cardiogenic shock in the context of a COVID-19-associated myocarditis and therapy with simultaneous veno-arterial extracorporeal membrane oxygenation (VA-ECMO) and percutaneous left ventricular decompression therapy with an Impella. The aim of this review is to provide an overview of therapeutic options for patients with COVID-19-associated myocarditis.
Conclusions: The majority of patients required a combination of two assist devices to achieve sufficient cardiac output until recovery of left ventricular ejection fraction. Due to the rapid onset of this fulminant cardiogenic shock immediate invasive bridging therapy in a specialized center was lifesaving.
Introduction: Studies of vocational ballet students are sparce. In particular, there is a lack of gender comparisons. The aim of the present study, therefore, was to give a musculoskeletal and sociodemographic description of the typical vocational ballet student in gender comparison. Methods: In this study, n = 414 female and n = 192 male students of the John Cranko School (JCS), aged between 5 and 22 years (Mean ± SD: 13.9 ± 3.5), were examined by an experienced orthopedist and dance physician. Results: Males started ballet (5.8/8.2 years, p < 0.001) and training at later age than females (13.5/14.6 years, p < 0.05). There was a high prevalence of low body weight among both sexes; however, particularly among female participants (58.4/16.2%, p < 0.001). Both sexes showed a large external rotation of the hip (f/m: 59/62°, p < 0.001), a large turnout (f/m: 82/86°, p < 0.01), high values for plantarflexion of the ankle joint (f/m: 72/68°, p < 0.001) and dorsiflexion of the metatarsophalangeal joint of the big toe (f/m: 90/87°, p < 0.001). Discussion: Differences in ballet-specific characteristics between genders (f/m) are converging and are smaller than described in the past. The particularly high prevalence of low body weight among students in the vocational training sector, particularly among females, highlights the need for deeper diagnostic investigation.
Structural brain morphometry as classifier and predictor of ADHD and reward-related comorbidities
(2022)
Attention deficit/hyperactivity disorder (ADHD) is one of the most common neurodevelopmental disorders, and around two-thirds of affected children report persisting problems in adulthood. This negative trajectory is associated with high comorbidity with disorders like obesity, depression, or substance use disorder (SUD). Decreases in cortical volume and thickness have also been reported in depression, SUD, and obesity, but it is unclear whether structural brain alterations represent unique disorder-specific profiles. A transdiagnostic exploration of ADHD and typical comorbid disorders could help to understand whether specific morphometric brain changes are due to ADHD or, alternatively, to the comorbid disorders. In the current study, we studied the brain morphometry of 136 subjects with ADHD with and without comorbid depression, SUD, and obesity to test whether there are unique or common brain alterations. We employed a machine-learning-algorithm trained to classify subjects with ADHD in the large ENIGMA-ADHD dataset and used it to predict the diagnostic status of subjects with ADHD and/or comorbidities. The parcellation analysis demonstrated decreased cortical thickness in medial prefrontal areas that was associated with presence of any comorbidity. However, these results did not survive correction for multiple comparisons. Similarly, the machine learning analysis indicated that the predictive algorithm grouped most of our ADHD participants as belonging to the ADHD-group, but no systematic differences between comorbidity status came up. In sum, neither a classical comparison of segmented structural brain metrics nor an ML model based on the ADHD ENIGMA data differentiate between ADHD with and without comorbidities. As the ML model is based in part on adolescent brains, this might indicate that comorbid disorders and their brain changes are not captured by the ML model because it represents a different developmental brain trajectory.
Objectives: The range of motion (ROM) of the cervical spine and postural stability are important for an economical and motorically adequate adaptation of the body to any situation. Therefore, this study aims to analyze whether these two components of postural and movement control can be influenced by means of a splint in a centric position compared to habitual occlusion.
Methods: 38 recreational male athletes volunteered. Cervical spine ROM was recorded using an ultrasound system and the a pressure measuring plate for postural stability (length of center of pressure (CoP) movement, area of CoP). The two dental occlusion conditions employed were the habitual occlusion and wearing a splint in an idealized, condylar position close to the centric position. Level of significance was set at ρ ≤ 0.05.
Results: The cervical spine mobility increased significantly by wearing the splint regarding rotation to the left (+3.9%) and right (+2.7%) and lateral flexion to the left (+4.4%) and right (+6.7%). Wearing the splint reduced the area of sway deflections by about 31.5% in the bipedal stance and by about 2.4% (left) and 28.2% (right) in the unipedal stance. The CoP trace was reduced in the sagittal plane by approximately 8.2% in the right single-leg stance.
Conclusions: The major findings seem to demonstrate that wearing a splint that keeps the jaw close to the centric relation may increase the cervical ROM and may improve balance stability in male recreational athletes. Changing the jaw relation in athletes can possibly aid the release of performance potentials by improving coordination skills.
Background: In order to determine possible pathological deviations in body weight distribution and body sway, it is helpful to have reference values for comparison: gender and age are two main influencing factors. For this reason, it was the aim of the present study to present reference values for women between 51 and 60 years of age.
Methods: For this study, 101 subjectively healthy female Germans aged between 51 and 60 years (55.16 ± 2.89 years) volunteered and were required to stand in a habitual posture on a pressure measuring platform.
Results: The average BMI of this age group was 25.02 ± 4.55 kg/m². The left and right foot showed an almost evenly balanced load distribution with a median load of 52.33% on the left foot [tolerance interval (TR) 38.00%/68.03%; confidence interval (CI) 51.00%/53.33%] and 47.67% on the right foot [TR 31.97%/62.00%; CI 46.67%/49.00%]. The measured median load of the forefoot was 33.33% [TR 21.37%/54.60%; CI 30.67%/36.00%] and that of the rear foot was 66.67% [TR 45.50%/78.63%; CI 64.00%/69.33%]. The median body sway in the frontal plane was 11 mm [TR 5.70 mm/26.30 mm; CI 10.00 mm/11.67 mm] and that of the sagittal plane was 16 mm [TR 7.37 mm/34.32 mm; CI 14.67 mm/18.67 mm]. The median ellipse area was 1.17 cm² [TR 0.29 cm²/4.96 cm²; CI 0.98 cm²/1.35 cm²], the median ellipse width was 0.91 cm [TR 0.42 cm/1.9 cm; CI 0.84 cm/1.02 cm] and its height was 0.40 cm [TR 0.22 cm/0.89 cm; CI 0.38 cm/0.43 cm].
Conclusions: The left-to-right ratio is almost balanced. The load distribution of the forefoot to the rear foot is approximately 1:2. The median body sway values for the frontal and sagittal planes (11 and 16 mm, respectively) agree with other values. The values for the height, body weight and the BMI are comparable to the values of average German women at this age; therefore, the measured values show a presentable cross section of women in the 51–60 age group in Germany. The present data can be used as a basis for women aged 51–60 years and can support the detection of possible dysfunctions as well as injury prevention in the parameters of postural control.
Background: In the COVID-19 pandemic, numerous researchers postponed their patient and public involvement (PPI) activities. This was mainly due to assumptions on patients’ willingness and skills to participate digitally. In fact, digital PPI workshops differ from in-person meetings as some forms of non-verbal cues and body language may be missing and technical barriers may exist. Within our project HYPERION-TransCare we adapted our PPI workshop series for intervention development to a digital format and assessed whether these digital workshops were feasible for patients, health care professionals and researchers.
Methods: We used a digital meeting tool that included communication via audio, video and chat. Discussions were documented simultaneously on a digital white board. Technical support was provided via phone and chat during the workshops and with a technical introduction workshop in advance. The workshop evaluation encompassed observation protocols, participants’ feedback via chat after each workshop on their chance to speak and the usability of the digital tools, and telephone interviews on patients’ and health professionals’ experiences after the end of the workshop series.
Results: Observation protocols showed an active role of moderators in verbally encouraging every participant to get involved. Technical challenges occurred, but were in most cases immediately addressed and solved. Participants median rating of their chance to speak and the usability of the digital tool was “very good”. In the evaluation interviews participants reported a change of perspective and mutual understanding as a main benefit from the PPI workshops and described the atmosphere as inclusive and on equal footing. Benefits of the digital format such as overcoming geographical distance, saving time and combining workshop participation with professional or childcare obligations were reported. Technical support was stressed as a pre-condition for getting actively involved in digital PPI.
Conclusions: Digital formats using different didactic and documentation techniques, accompanied by technical support, can foster active patient and public involvement. The advantages of digital PPI formats such as geographical flexibility and saving time for participants as well as the opportunity to prepare and hold workshops in geographically stretched research teams persists beyond the pandemic and may in some cases outweigh the advantages of in-person communication.
Although, during the past decades, substantial advances emerged in identifying major local and systemic factors contributing to initiation and progression of osteoarthritis (OA), some neuroendocrine mechanisms are still not understood or even neglected when thinking about novel therapeutic options. One of which is the sympathetic nervous system that exhibits various OA-promoting effects in different tissues of the joint. Interestingly, the β2-adrenoceptor (AR) mediates the majority of these effects as demonstrated by several in vitro, in vivo as well as in clinical studies. This review article does not only summarize studies of the past two decades demonstrating that the β2-AR plays an OA-promoting role in different tissues of the joint but also aims to encourage the reader to think about next-level research to discover novel and innovative preventive and/or therapeutic strategies targeting the β2-AR in OA.
Das Hepatoblastom ist ein embryonaler Lebertumor, dessen Zellen unterschiedliche unreife Stadien aufweisen. Aufgrund dieser Unreife ist die Identifizierung von Krebsstammzellen erschwert, die in diesem Tumor vermutet und für Rückfälle verantwortlich gemacht werden. In Vorarbeiten konnte eine Krebsstammzellpopulation mit der Kombination der hämatopoetischen Stammzellmarker CD90 und CD34 sowie dem „oval cell“ OV-6-Antikörper in den etablierten Hepatoblastomzelllinien HuH6 und HepG2 detektiert werden. Diese CD34+OV-6+CD90+ Zellen wiesen eine erhöhte Expression von Pluripotenzfaktoren auf und zeichneten sich durch ein erhöhtes Migrationsverhalten aus.
In der hier vorgelegten Arbeit wurden zunächst Tumor-Sphäroid-Assays durchgeführt um diese Population als Krebsstammzellen zu bestätigen, da nur Krebsstammzellen unter den gegebenen Umständen wachsen können. Diese waren im Anschluss wieder in der Lage, in „normalem Medium“ zu differenzieren. Des Weiteren wurden die Zelllinien mit dem Standardtherapeutikum Cisplatin behandelt. Da Krebsstammzellen als chemoresistent gelten, konnte in der überlebenden Zellpopulation auch eine Anreicherung der CD34+OV-6+CD90+ Zellen beobachtet werden. Zusätzlich ließ sich eine weitere CD34+OV-6+CD90+ Population identifizieren, deren Expression aller drei Marker schwächer war und die bei steigenden Cisplatin-Konzentrationen den Großteil der CD34+OV-6+CD90+ Population ausmachte.
Neben den erhöhten Transkriptmengen der Pluripotenzmarker Oct4 und Nanog zeichneten sich die CD34+OV-6+CD90+ Krebsstammzellen durch eine verstärkte Expression der aktivierungsinduzierten Zytidin-Desaminase AID aus. AID wirkt induzierend auf die Transkription beider Pluripotenzmarker. Daher könnte es auch bei Krebsstammzellen eine Rolle bei der Induktion von Pluripotenz und bei ihrer langfristigen Erhaltung spielen. Dies unterstützend legten die verminderten Transkriptmengen der Pluripotenzgene nach einem AID siRNA Knock-Down eine Abhängigkeit des Stammzellcharakters von diesem Faktor nahe. Um einen Effekt von Therapeutika, die inhibitorisch auf AID wirken, auf Krebsstammzellen zu untersuchen, wurden die Zellen mit den DNMT-Inhibitoren Decitabine und Zebularine sowie dem HSP90-Inhibitor Tanespimycin behandelt. Tatsächlich konnte vor allem in den HuH6-Zellen ein verminderter Anteil der Krebsstammzellpopulation durch die drei Substanzen beobachtet werden. Wurden die Zellen im Anschluss mit dem Standardzytostatikum Cisplatin behandelt, führte allerdings eine Vorbehandlung mit Zebularine oder Decitabine zu einer starken Anreicherung von Krebsstammzellen. Dies war vor allem auf Zellen mit dem schwach positiven CD34+OV-6+CD90+ Expressionsprofil zurückzuführen, die chemo-induziert zu sein scheinen. Zwar erscheint die Mehrheit der Tumorzellen eliminiert zu werden, jedoch lassen diese Ergebnisse die Entstehung von chemo-induzierten Krebsstammzellen vermuten, die langfristig für einen Rückfall verantwortlich sein könnten. Daher ist von einer Ergänzung der Therapie mit diesen Substanzen abzusehen. Eine Vorbehandlung mit Tanespimycin hingegen konnte im Vergleich zur alleinigen Cisplatin-Behandlung wirksam den Anteil der Krebsstammzellen reduzieren. Interessanterweise war dies nicht auf einen verstärkten Zelltod der Krebsstammzellen, sondern vielmehr auf eine durch Tanespimycin bewirkte Differenzierung derselben zurückzuführen. Diese spiegelte sich auch in einer verminderten Expression von Pluripotenzmarkern auf mRNA-Ebene im Vergleich zur alleinigen Cisplatin-Behandlung wider.
Somit präsentierte sich Tanespimycin als potenter Inhibitor von Krebsstammzellen. Auch wenn weitere vorklinische und klinische Tests und Untersuchungen erfolgen müssen, stellt Tanespimycin bzw. die Substanzklasse der HSP90-Inhibitoren einen interessanten und vielversprechenden Kandidaten für eine Ergänzung der Standardtherapie vor allem bei behandlungsresistenten und rekurrenten High-Risk-Hepatoblastomen dar.
Inflammation is a regulated reaction of the body to control a threat such as infection or injury. An efficient resolution of inflammation is critical to prevent the development of chronic inflammation and to restore tissue homeostasis. Macrophages (Mf) play a crucial role in the onset, but also in the resolution of inflammation, because they phagocytose and eliminate pathogens and tissue debris. Efficient efferocytosis, i.e. the engulfment of apoptotic cells, represents an important trigger for the onset of the resolution response and contributes to the pro-resolving reprogramming of Mf. Despite the importance of post- transcriptional modes of regulation during the resolution phase and translational control as a key node modulating gene expression in immune cells, relevant translational alterations remain largely elusive.
In the present study, I aimed to identify translationally regulated targets in inflammatory primary murine Mf upon resolution-promoting efferocytosis. To this end, I used total RNA-sequencing as well as de novo proteomics analyses to determine global transcriptional and translational changes. Sequencing data confirmed that efferocytosis induced a pro-resolution signature in inflammatory Mf and pointed towards translational regulation because the related integrated stress response was enriched upon efferocytosis. While changes of gene expression between efferocytic and non-efferocytic Mf appeared rather small at the transcriptional level, I observed considerable differences at the level of de novo synthesized proteins. This finding suggests a regulation at the level of translation. Furthermore, the tight connection between translational and metabolic changes was confirmed by enriched metabolism-associated terms of targets upregulated by efferocytosis at both RNA and de novo protein level. Interestingly, analysis of translationally regulated targets in response to inflammatory stimulation showed reduced translation for most targets, with only little impact of efferocytosis. Among those targets, I identified pro-resolving matrix metallopeptidase 12 (Mmp12) as a novel candidate, which showed translational repression during early inflammation and translational increase during the resolution phase. Noteworthy, a first indicator for a potential translation regulatory component of Mmp12 were the extremely high mRNA levels and not overly high de novo protein levels. Validation experiments recapitulated a slight elevation of Mmp12 mRNA expression and a significant downregulation of MMP12 intracellular protein levels in inflammatory Mf, as observed in the RNA-seq and de novo proteomics datasets. To investigate whether the discrepancy in mRNA and protein expression were due to changes in translation, I applied polysomal fractionation analysis to determine the translational status of Mmp12. Inflammatory Mf displayed a significantly lower relative Mmp12 mRNA abundance in the late polysomes compared to naïve Mf, suggesting reduced translational efficiency upon inflammatory stimulation. Consequently, extracellular MMP12 levels in the supernatant of inflammatory Mf decreased, although with a slight delay.
The functional impact of attenuated Mmp12 translation upon inflammatory stimulation was assessed in migration assays. While siRNA-mediated knockdown of Mmp12 did not alter Mf migration on uncoated plates, it increased migration 3-fold on matrigel/elastin-coated plates. Importantly, the increase in migrated distance driven by siMmp12 could be lowered by the addition of exogenous recombinant MMP12 protein. In line with reduced Mmp12 translation and MMP12 protein in inflammatory Mf, I observed a significant increase in cell migration on matrigel/elastin-coated plates, while it remained unaltered on uncoated plates. Consequently, Mf elastase MMP12 degrades elastin, thereby cell migration along elastin fibers is diminished. In inflammatory Mf, Mmp12 is translationally downregulated, thereby enhancing the migratory capacity.
In summary, the present study identifies a substantial contribution of translational regulation in the course of inflammation shown by high changes between inflammatory naïve and efferocytic Mf at the de novo proteomic level. Specifically, I was able to determine the translational regulation of pro-resolving Mmp12, which is repressed during early inflammation and recovers during the resolution phase. Functionally, translational control of MMP12 emerged as a strategy to alter the migratory properties of Mf, enabling enhanced, matrix- dependent migration of Mf during the early inflammatory phase, while restricting migration during the resolution phase.
Aryl hydrocarbon receptor-dependent and -independent pathways mediate curcumin anti-aging effects
(2022)
The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor whose activity can be modulated by polyphenols, such as curcumin. AhR and curcumin have evolutionarily conserved effects on aging. Here, we investigated whether and how the AhR mediates the anti-aging effects of curcumin across species. Using a combination of in vivo, in vitro, and in silico analyses, we demonstrated that curcumin has AhR-dependent or -independent effects in a context-specific manner. We found that in Caenorhabditis elegans, AhR mediates curcumin-induced lifespan extension, most likely through a ligand-independent inhibitory mechanism related to its antioxidant activity. Curcumin also showed AhR-independent anti-aging activities, such as protection against aggregation-prone proteins and oxidative stress in C. elegans and promotion of the migratory capacity of human primary endothelial cells. These AhR-independent effects are largely mediated by the Nrf2/SKN-1 pathway.
The pathophysiology of Takotsubo Syndrome (TTS) is not completely understood and the trigger of sudden cardiac death (SCD) in TTS is not clear either. We therefore sought to find an association between TTS and primary electrical diseases. A total of 148 TTS patients were analyzed between 2003 and 2017 in a bi-centric manner. Additionally, a literature review was performed. The patients were included in an ongoing retrospective cohort database. The coexistence of TTS and primary electrical diseases was confirmed in five cases as the following: catecholaminergic polymorphic ventricular tachycardia (CPVT, 18-year-old female) (n = 1), LQTS 1 (72-year-old female and 65-year-old female) (n = 2), LQTS 2 (17-year-old female) (n = 1), and LQTS in the absence of mutations (22-year-old female). Four patients suffered from malignant tachyarrhythmia and recurrent syncope after TTS. Except for the CPVT patient and one LQTS 1 patient, all other cases underwent subcutaneous ICD implantation. An event recorder of the CPVT patient after starting beta-blocker did not detect arrhythmias. The diagnosis of primary electrical disease was in 80% of cases unmasked on a TTS event. This diagnosis triggered a family clinical and genetic screening confirming the diagnosis of primary electrical disease. A subsequent literature review identified five cases as the following: a congenital atrioventricular block (n = 1), a Jervell and Lange-Nielsen Syndrome (n = 1), and a family LQTS in the absence of a mutation (n = 2), LQTS 2 (n = 1). A primary electrical disease should be suspected in young and old TTS patients with a family history of sudden cardiac death. In suspected cases, e.g., ongoing QT interval prolongation, despite recovery of left ventricular ejection fraction a family screening is recommended.