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Cell type-specific purifying selection of synonymous mitochondrial DNA variation
Get PDFWhile somatic variants are well-characterized drivers of tumor evolution, their influence on cellular fitness in nonmalignant contexts remains understudied. We identified a mosaic synonymous variant (m.7076A > G) in the mitochondrial DNA (mtDNA)-encoded cytochrome c-oxidase subunit 1 (MT-CO1, p.Gly391=), present at homoplasmy in 47% of immune cells from a healthy donor. Single-cell multiomics revealed strong, lineage-specific selection against the m.7076G allele in CD8(+) effector memory T cells, but not other T cell subsets, mirroring patterns of purifying selection of pathogenic mtDNA alleles. The limited anticodon diversity of mitochondrial tRNAs forces m.7076G translation to rely on wobble pairing, unlike the Watson–Crick–Franklin pairing used for m.7076A. Mitochondrial ribosome profiling confirmed stalled translation of the m.7076G allele. Functional analyses demonstrated that the elevated translational and metabolic demands of short-lived effector T cells (SLECs) amplify dependence on MT-CO1, driving this selective pressure. These findings suggest that synonymous variants can alter codon syntax, impacting mitochondrial physiology in a cell type–specific manner
Platelet-rich plasma - a comprehensive review of isolation, activation, and application
No full textPlatelets and platelet enriched products have been widely studied for their roles in promoting cell proliferation, migration, and tissue regeneration, making them highly interesting for clinical applications such as traumatology, dental, orthopaedic, and plastic surgery. However, their clinical adoption remains limited, partly due to fragmented and inconsistent data. Previous reviews have explored various applications of PRP therapies, but no comprehensive work has systematically mapped their processing methods, treatment modalities, and applications alongside clinical outcomes. This review thus aims to provide a thorough analysis of platelet-rich products, including platelet-rich plasma and platelet lysate, critically assessing their therapeutic potential. Variability in factors such as platelet and leukocyte content, red blood cell contamination, and activation methods complicates the clinical implementation and standardization of plateletrich products. Herein, we examine platelet structure, function, and growth factors (e.g., PDGF, VEGF, and TGF-β) essential for tissue repair and regeneration, alongside manufacturing processes and isolation techniques impacting product quality. Additionally, we explore platelet recovery, activation strategies (chemical, physical, enzymatic), application forms, patient-related variables, and the immune-modulatory roles of platelets in inflammation, wound healing, and immune response regulation
Non-autonomous Vnd acts with autonomous Appl during mushroom body axon growth in Drosophila
No full textThe Amyloid Precursor Protein (APP) is associated with Alzheimer’s disease. Appl is the single Drosophila APP ortholog and is expressed in all neurons throughout development. Appl was previously shown to cell-autonomously modulate axon outgrowth in the mushroom bodies (MBs), the fly olfactory memory center. However, we found that Appl(d), the only reported null allele, affects the normal function of vnd, the gene just proximal to Appl. To decipher developmental defects specifically due to a loss of only Appl function, we generated a precise Appl null allele (Appl(C2.1)) by CRISPR/Cas9 genomic engineering. With Appl(C2.1), we confirmed the partial requirement for Appl in MB axon outgrowth. We also produced new CRISPR vnd alleles removing either vnd-B or vnd-A function. We report here that vnd is also required for MB β-branch axon outgrowth and to a much greater extent than Appl itself. Moreover, vnd is expressed in neurons close to, but not within, the MB during development and is required non-cell-autonomously for MB axon outgrowt
Sub-type specific connectivity between CA3 pyramidal neurons may underlie their sequential activation during sharp waves
Get PDFThe CA3 region of the hippocampus is the major site of sharp wave initiation, and a brain region crucially involved in learning and memory. Highly recurrent connectivity within its excitatory network is thought to underlie processes involved in memory formation. Recent work has indicated that distinct subpopulations of pyramidal neurons within this region may contribute differently to network activity, including sharp waves, in CA3. Exactly how these contributions may arise is not yet known. Here, we disentangle the local connectivity between two distinct CA3 cell types in mice: thorny and athorny pyramidal cells. We find an asymmetry in the connectivity between these two populations, with athorny cells receiving strong input from both athorny and thorny cells. Conversely, the thorny cell population receives very little input from the athorny population. Computational modeling suggests that this connectivity scheme may determine the sequential activation of these cell types during large network events such as sharp waves
Impact of cellular composition and T-cell senescence of mononuclear cell concentrates on the manufacturing process of chimeric antigen receptor (CAR) T-cells
Get PDFBACKGROUND: Apheresis procedure of autologous lymphocytes competent for proliferation and expansion is a crucial step in the production of chimeric antigen receptor (CAR) T-cells. Previous therapies or disease status prior to collection may negatively impact the collections. STUDY DESIGN AND METHODS: We performed a retrospective analysis with the aim to determine cellular factors in association with the collection of autologous T-cells and subsequent CAR T manufacturing toward tisagenlecleucel (tisa-cel). Between February 2019 and February 2022, 63 collections of 54 patients were performed for subsequent therapy with tisa-cel. RESULTS: We observed no difference in median CD3+ cell yields according to the number of prior therapy lines (>3 vs. ≤3, p = .335), prior treatment with bendamustine (p = .954) or marrow infiltration (p = .634). Fifty-six collections were sent for manufacturing, of which 22 (39%) resulted in manufacturing failures, namely terminations (n = 12) or out-of-specification events (n = 10). Collections resulting in manufacturing failures yielded significantly lower CD3+ (p = .005), CD3+CD4+ (p = .044), and non-senescent CD3+CD27+CD28+ (p = .003) counts. Multivariable analysis identified the absolute number of CD3+CD27+CD28+ cells as relevant, with a calculated cut-off of ≥34.58 × 10(8) CD3+CD27+CD28+ cells for 89.5% probability of successful CAR T-cell production. DISCUSSION: In summary, we report a positive influence of a higher number of non-senescent Τ-cells on successful manufacturing. Further analyses are required to determine measures for further optimization of collection outcomes
Efficient motion-corrected image reconstruction for 3D cardiac MRI through stochastic optimisation
Get PDFOBJECTIVE: Motion-corrected image reconstruction (MCIR) allows for fast and efficient cardiac magnetic resonance imaging (MRI) acquisition with predictable scan times. Since data obtained in all phases of respiratory and cardiac motion can be exploited, the duration of the scan is not affected by changes in heart rate or irregular breathing patterns. Achieving high-quality reconstructions from MCIR data typically requires iterative optimisation algorithms with regularisation, where reconstruction time increases with the number of motion states. This is particularly relevant in cardiac MRI, where both cardiac and respiratory motion corrections are necessary to minimise motion artefacts. APPROACH: In this work, we present a stochastic optimisation approach for efficient MCIR of 3D cardiac MRI images using the stochastic primal dual hybrid gradient (SPDHG) algorithm. MAIN RESULTS: In phantom experiments with simulated motion, we demonstrate the improved convergence rates of SPDHG with respect to deterministic algorithms, while maintaining image quality. Convergence is improved both in terms of reconstruction times and computational effort. We validate the method’s effectiveness on an in vivo 3D whole-heart cardiac MR scan. The in vivo method demonstrates that the motion compensation method we use allows for non-rigid deformations and irregular breathing patterns. SIGNIFICANCE: This study demonstrates that stochastic algorithms can converge significantly faster than deterministic algorithms for MCIR, especially for a large number of motion states. With the proposed approach, increasing the number of motion states reduces the number of epochs required to reconstruct the image and therefore it is no longer necessary to balance the competing requirements of accurate motion correction and computational effort
Unveiling tissue-specific transcriptional adaptations in iPSC-derived fibroblasts via co-culture systems
Get PDFBACKGROUND: Induced pluripotent stem cell-derived fibroblasts (iFBs) hold promise for autologous disease modelling, but their ability to replicate tissue-specific fibroblast characteristics remains unclear. Fibroblasts exhibit significant heterogeneity, with distinct subtypes playing critical roles in organ function and integrity. This study investigates whether iFBs can acquire tissue-specific transcriptional profiles through co-culture with cells from different germ layers, including skin (keratinocytes), heart (cardiomyocytes), gut (intestinal cells), and lung (bronchial epithelial cells). METHODS: iFBs were co-cultured directly or indirectly with organ-specific cell types, followed by bulk RNA sequencing and pathway analysis. Transcriptional profiles were compared to primary fibroblasts using principal component analysis (PCA), large single-cell databases of over 20,000 cells for single-cell deconvolution and targeted qPCR validation. Statistical significance was assessed via one-way ANOVA. RESULTS: Transcriptomic analysis revealed that iFBs exhibit transcriptional plasticity, adopting molecular phenotypes aligned with their co-culture environment across all germ layers. Paracrine signalling induced transient tissue-specific changes in indirectly co-cultured iFBs, but sustained interactions were required for stable adaptations. Pathway analysis highlighted functional shifts, such as TGF-β activation in cardiac iFBs and ECM remodelling in dermal iFBs. However, single-cell deconvolution showed incomplete tissue specification, with iFBs retaining mixed fibroblast subpopulations. CONCLUSIONS: These findings demonstrate that iFBs can adopt tissue-specific transcriptional profiles, supporting their potential for modelling fibrotic microenvironments in 3D in vitro systems. However, the partial and transient nature of these adaptations underscores the need to validate whether transcriptional changes translate to functional fibroblast behaviours, such as ECM dysregulation or aberrant TGF-β signalling, in complex tissue models. Optimising co-culture conditions to stabilise these phenotypes will be critical for leveraging iFBs in fibrosis research, drug screening, and personalised disease modelling
2025 ESC Guidelines for the management of myocarditis and pericarditis - developed by the task for ce for the management of myocarditis and pericarditis of the European Society of Cardiology (ESC) - endorsed by the Association for European Paediatric and Congenital Cardiology (AEPC) and the European Association for Cardio-Thoracic Surgery (EACTS)
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Antithrombin-binding heparan sulfate is ubiquitously expressed in epithelial cells and suppresses pancreatic tumorigenesis
Get PDF3-O-sulfation of heparan sulfate (HS) is the key determinant for binding and activation of Antithrombin III (AT). This interaction is the basis of heparin treatment to prevent thrombotic events and excess coagulation. Antithrombin-binding HS (HS(AT)) is expressed in human tissues, but is thought to be expressed in the subendothelial space, mast cells, and follicular fluid. Here we show that HS(AT) is ubiquitously expressed in the basement membranes of epithelial cells in multiple tissues. In the pancreas, HS(AT) is expressed by healthy ductal cells and its expression is increased in premalignant pancreatic intraepithelial neoplasia lesions (PanINs), but not in pancreatic ductal adenocarcinoma (PDAC). Inactivation of HS3ST1, a key enzyme in HS(AT) synthesis, in PDAC cells eliminated HS(AT) expression, induced an inflammatory phenotype, suppressed markers of apoptosis, and increased metastasis in an experimental mouse PDAC model. HS(AT)-positive PDAC cells bind AT, which inhibits the generation of active thrombin by tissue factor (TF) and Factor VIIa. Furthermore, plasma from PDAC patients showed accumulation of HS(AT) suggesting its potential as a marker of tumor formation. These findings suggest that HS(AT) exerts a tumor suppressing function through recruitment of AT and that the decrease in HS(AT) during progression of pancreatic tumorigenesis increases inflammation and metastatic potential