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Characterizing uveal melanoma patients with peritoneal metastases: a retrospective single-center analysis
Get PDFBACKGROUND: Metastatic uveal melanoma (mUM) is an aggressive cancer predominately affecting the liver. Peritoneal metastases (PM) occur rarely, and there is limited knowledge about this subgroup´s clinical course and biology. METHODS: We analyzed 41 mUM patients with confirmed PM from the Charité-Universitätsmedizin Berlin database, focusing on clinical characteristics, immune cell infiltrates, genetic alterations and tumor mutational burden (TMB). RESULTS: The incidence of PM in mUM was 4.27 %. Metastatic disease was diagnosed 3.6 years after primary UM, with PM developing later (median: 4.7 years). Median overall survival (OS) from mUM diagnosis was 22.4 months. Prognosis correlated with metastatic pattern. Patients presenting with synchronous liver and peritoneal metastases or primary hepatic metastases followed by secondary peritoneal dissemination showed a median OS of 19.7 and 17.7 months, respectively. However, PM patients with exclusive extrahepatic disease at diagnosis of mUM had a significantly longer OS of 48.6 months and this metastatic pattern showed highly significant correlation with low and intermediate genetic risk. Metastasis-free survival and OS upon mUM diagnosis were significantly shorter in patients with high-risk UM tumors. TMB also correlated with metastatic pattern, being lowest in patients presenting with only extrahepatic disease. Higher TMB was generally associated with shorter OS. CONCLUSION: PM in mUM patients is rare and in contrast to other extra-abdominal tumors does not worsen prognosis. Prognosis is greatly influenced by the metastatic pattern, which is determined by tumor biology, as evidenced by its correlation with genetic risk groups and TMB
Touch inhibits cold: non-contact cooling suggests a thermotactile gating mechanism
Get PDFSkin stimuli reach the brain via multiple neural channels specific for different stimulus types. These channels interact in the spinal cord, typically through inhibition. Inter-channel interactions can be investigated by selectively stimulating one channel and comparing the sensations that result when another sensory channel is or is not concurrently stimulated. Applying this logic to thermal–mechanical interactions proves difficult, because most existing thermal stimulators involve skin contact. We used a novel non-tactile stimulator for focal cooling (9 mm(2)) by using thermal imaging of skin temperature as a feedback signal to regulate exposure to a dry-ice source. We could then investigate how touch modulates cold sensation by delivering cooling to the human hand dorsum in either the presence or absence of light touch. Across three signal detection experiments, we found that sensitivity to cooling was significantly reduced by touch. This reduction was specific to touch, as it did not occur when presenting auditory signals instead of the tactile input, making explanations based on distraction or attention unlikely. Our findings suggest that touch inhibits cold perception, recalling interactions of touch and pain previously described by Pain Gate Theory
Roadmap for alleviating the manifestations of ageing in the cardiovascular system
No full textAgeing of the cardiovascular system is associated with frailty and various life-threatening diseases. As global populations grow older, age-related conditions increasingly determine healthspan and lifespan. The circulatory system not only supplies nutrients and oxygen to all tissues of the human body and removes by-products but also builds the largest interorgan communication network, thereby serving as a gatekeeper for healthy ageing. Therefore, elucidating organ-specific and cell-specific ageing mechanisms that compromise circulatory system functions could have the potential to prevent or ameliorate age-related cardiovascular diseases. In support of this concept, emerging evidence suggests that targeting the circulatory system might restore organ function. In this Roadmap, we delve into the organ-specific and cell-specific mechanisms that underlie ageing-related changes in the cardiovascular system. We raise unanswered questions regarding the optimal design of clinical trials, in which markers of biological ageing in humans could be assessed. We provide guidance for the development of gerotherapeutics, which will rely on the technological progress of the diagnostic toolbox to measure residual risk in elderly individuals. A major challenge in the quest to discover interventions that delay age-related conditions in humans is to identify molecular switches that can delay the onset of ageing changes. To overcome this roadblock, future clinical trials need to provide evidence that gerotherapeutics directly affect one or several hallmarks of ageing in such a manner as to delay, prevent, alleviate or treat age-associated dysfunction and diseases
Diminazene aceturate (DIZE) ameliorates hypertension and induces anxiolytic- and antidepressant-like effects in TGR(Mren2)27
No full textINTRODUCTION: Diminazene aceturate (DIZE) was described as an angiotensin-converting enzyme 2 (ACE2) activator. ACE2/Angiotensin-(1-7)/Mas receptor axis presents protective actions on cardiovascular diseases and plays an important modulatory role in the neurobiology of mood and anxiety disorders. OBJECTIVES: To evaluate the effects of chronic intracerebroventricular (ICV) treatment with DIZE on blood pressure, anxiety- and depression-like behaviors in hypertensive transgenic (mRen2)27 rats (TGR). METHODS: Male TGR and Sprague-Dawley rats (10-12 weeks old) were subjected to chronic ICV infusion of DIZE (1.0 μg/h for 7 days). Blood pressure and heart rate were measured by tail plethysmography and anxiety- and depression-like behaviors were evaluated through elevated plus maze, marble burying and forced swim tests, respectively. RESULTS: Treatment with DIZE induced a significant reduction in mean arterial pressure in both TGR and SD rats. A decrease in heart rate was only observed in the hypertensive animals. Additionally, treatment with DIZE attenuated the anxiety- and depression-like behaviors that were observed in TGR. CONCLUSION: DIZE has central anti-hypertensive, anxiolytic, and anti-depressive effects
Role of intestinal barrier disruption to acute-on-chronic liver failure
No full textAcute-on-chronic liver failure (ACLF) is a severe condition in patients with decompensated liver cirrhosis, marked by high short-term mortality. Recent experimental and clinical evidence has linked intestinal dysfunction to both the initiation of ACLF as well as disease outcome. This review discusses the significant role of the gut-liver axis in ACLF pathogenesis, highlighting recent advances. Gut mucosal barrier disruption, gut dysbiosis, and bacterial translocation emerge as key factors contributing to systemic inflammation in ACLF. Different approaches of therapeutically targeting the gut-liver axis via farnesoid X receptor agonists, nonselective beta receptor blockers, antibiotics, and probiotics are discussed as potential strategies mitigating ACLF progression. The importance of understanding the distinct pathophysiology of ACLF compared with other stages of liver cirrhosis is highlighted. In conclusion, research findings suggest that disruption of intestinal integrity may be an integral component of ACLF pathogenesis, paving the way for novel diagnostic and therapeutic approaches to manage this syndrome more effectively
Benchmarking of quantitative proteomics workflows for limited proteolysis mass spectrometry
Get PDFLimited proteolysis coupled with mass spectrometry (LiP-MS) has emerged as a powerful technique for detecting protein structural changes and drug-protein interactions on a proteome-wide scale. However, there is no consensus on the best quantitative proteomics workflow for analyzing LiP-MS data. In this study, we comprehensively benchmarked two major quantification approaches-data-independent acquisition (DIA) and tandem mass tag (TMT) isobaric labeling-in combination with LiP-MS, using a drug-target deconvolution assay as a model system. Our results show that while TMT labeling enabled the quantification of more peptides and proteins with lower coefficients of variation (CVs), DIA-MS exhibited greater accuracy in identifying true drug targets and stronger dose-response correlation in protein targets peptides. Additionally, we evaluated the performance of freely available (FragPipe) versus commercial (Spectronaut) software tools for DIA-MS analysis, revealing that the choice between precision (FragPipe) and sensitivity (Spectronaut) largely depends on the specific experimental context. Our findings underscore the importance of selecting the appropriate LiP-MS quantification strategy based on the study objectives. This work provides valuable guidelines for researchers in structural proteomics and drug discovery, and highlights how advancements in mass spectrometry instrumentation, such as the Astral mass spectrometer, may further improve sensitivity and protein sequence coverage, potentially reducing the need for TMT labeling
‘EarlyAMDRate’: a grading instrument for OCT-based assessment of early lesions caused by age-related macular degeneration
Get PDFBACKGROUND AND OBJECTIVES: Long before any signs of age-related macular degeneration (AMD) become clinically noticeable, the disease starts with accumulation of deposits of extracellular debris and formation of lesions within the outermost layers of the retina. For a reliable imaging of lesions in these early stages, optical coherence tomography (OCT) turned out to be largely preferable to colour fundus photography. However, an adequate grading instrument for Early-AMD lesions within OCT data is missing in the literature as yet. The present paper aims to fill this gap. METHODS: ‘EarlyAMDRate’, an instrument for OCT-based grading of Early-AMD lesions, is presented and documented. It comprises a questionnaire assessing a given lesion with respect to its relative position and interaction with the surrounding retinal layers, its brightness, special properties and state of progression (if applicable). Furthermore, the grading procedure includes a graphical masking of the lesion within the OCT image. RESULTS: For a consecutive sample of N = 100 Early-AMD patients, the ‘EarlyAMDRate’ grading instrument has been applied to leading OCT scans. Examples of masked lesions and processed grading questionnaires are provided. Both raw lesion diameters and cutting sizes follow a log-normal sample distribution. CONCLUSIONS: ‘EarlyAMDRate’ allows for unprecedented detail of description for single Early-AMD lesions which is adequate to the precision of underlying OCT imaging. The obtained grading information allows for a tracking of single lesions and their properties over time as well as for the generation of well-differentiated metric phenotypes for description of Early-AMD
Prior chemotherapy deteriorates T-cell quality for CAR T-cell therapy in B-cell non-Hodgkin's lymphoma
Get PDFBACKGROUND: Chimeric antigen receptor (CAR) T-cell therapy depends on T cells that are genetically modified to recognize and attack cancer cells. Their effectiveness thus hinges on the functionality of a patient's own T cells. Since CAR T-cell therapy is currently only approved for advanced cancers after at least one line of chemotherapy, we evaluated the potential negative effects of prior exposure to chemotherapy on T-cell functionality. METHODS: We studied T cells of two B-cell non-Hodgkin's lymphoma patient cohorts, one collected before treatment (pre-therapy) and the other after one or more (median 3) lines of chemotherapy (post-therapy). Leveraging advanced multiparameter flow cytometry, single-cell RNA sequencing (scRNA-seq), whole-genome DNA methylation arrays and in vitro functionality testing of generated CAR T cells, we compared patient samples in their suitability for effective CAR T-cell therapy. RESULTS: We discovered significant modifications in T-cell subsets and their transcriptional profiles secondary to chemotherapy exposure. Our analysis revealed a discernible shift towards phenotypically more differentiated T cells and an upregulation of markers indicative of T-cell exhaustion. Additionally, scRNA-seq and DNA methylation analyses revealed gene expression and epigenetic changes associated with diminished functionality in post-therapy T cells. Cytotoxicity assays demonstrated superior killing efficacy of CAR T cells derived from treatment-naïve patients compared with those with chemotherapy history. CONCLUSIONS: These findings corroborate that employing T cells collected prior to frontline chemotherapy could enhance the effectiveness of CAR T-cell therapy and improve patient outcomes
Penta-ALFA-tagged substrates for self-labelling tags allow signal enhancement in microscopy
Get PDFSelf-labelling proteins like SNAP- and HaloTag have advanced imaging in life sciences by enabling live-cell labeling with fluorophore-conjugated substrates. However, the typical one-fluorophore-per-protein system limits signal intensity. To address this, we developed a strategy using the ALFA-tag system, a 13-amino acid peptide recognized by a bio-orthogonal and fluorescently labelled nanobody, for signal amplification. We synthesized a pentavalent ALFA(5) peptide and used an azidolysine for conjugation with a Cy5-modified SNAP- or HaloTag ligand through strain-promoted click chemistry. In vitro measurements on SDS-PAGE showed labelling, and the peptides covalently reacted with their respective tag. HEK293 cells expressing SNAP- and HaloTag-mGluR2 fusion proteins were labeled with ALFA(5)-Cy5 substrates, and confocal microscopy revealed a significant enhancement in the far-red signal intensity upon nanobody addition, as quantified by integrated signal density ratios. Comparisons between SNAP- and HaloTag substrates showed superior performance for the latter, achieving better signal-to-noise and signal-to-background ratios, as well as overall signal intensity in plasma membrane-localized regions. Our results demonstrate the potential of ALFA-tag-based systems to amplify SLP fluorescent signals. This strategy combines the photostability of synthetic fluorophores with multivalent labeling, providing a powerful tool for advanced imaging applications including super-resolution in cells. Its versatility is expandable across diverse protein systems and colors
Scalable image-based visualization and alignment of spatial transcriptomics datasets
Get PDFWe present the “spatial transcriptomics imaging framework” (STIM), an imaging-based computational framework focused on visualizing and aligning high-throughput spatial sequencing datasets. STIM is built on the powerful, scalable ImgLib2 and BigDataViewer (BDV) image data frameworks and thus enables novel development or transfer of existing computer vision techniques to the sequencing domain characterized by datasets with irregular measurement-spacing and arbitrary spatial resolution, such as spatial transcriptomics data generated by multiplexed targeted hybridization or spatial sequencing technologies. We illustrate STIM’s capabilities by representing, interactively visualizing, 3D rendering, automatically registering, and segmenting publicly available spatial sequencing data from 13 serial sections of mouse brain tissue and from 19 sections of a human metastatic lymph node. We demonstrate that the simplest alignment mode of STIM achieves human-level accuracy