Fatty acids (FAs) play essential roles in fetal development and physiological processes, serving as precursors for signaling molecules, structural components of cellular membranes, and components of lipids in energy reserves. The long-term storage of FAs in adipocyte triacylglycerols provides the growing fetus with structurally and functionally different FAs, which have diverse effects on developmental and metabolic health. Adipose tissue samples were obtained from perirenal, omental, mediastinal, mesenteric, subcutaneous, and periorbital depots of six pregnant ewes and six fetuses. Histological analysis of adipocyte sizes was performed using the QuPath and Adipocyte Tools, and gas chromatography-mass spectrometry was employed to analyze FA compositions. Principal component analysis was utilized to identify patterns in FA profiles separating maternal and fetal tissues. Analysis of adipocyte size distribution revealed significantly larger adipocytes in ewes compared with fetuses. Maternal perirenal and omental adipose tissues contained the largest cells. Monounsaturated FAs and biologically active long-chain n-3 and n-6 polyunsaturated FAs were more abundant in fetal tissues, while saturated FAs were more abundant in maternal tissues. In conclusion, fetal and maternal adipose tissues demonstrated significant differences in morphology and FA composition, reflecting their distinct functional roles. While fetal FA composition is heavily influenced by fetoplacental FA transfer, and the observed FA patterns are consistent with endogenous metabolic processing in fetuses, further transcriptomic data will be required for more detailed metabolic interpretation. Still, these findings could reflect a degree of metabolic independence of fetuses in this ruminant model and help generate hypotheses for future translational studies.

Calpeptin, a calpain inhibitor with potential for treating inflammatory diseases, reduces extracellular vesicle (EV) secretion. While adipose tissue is a recognized target of calpeptin, its effects on lipid metabolism remain unknown. We investigated calpeptin’s impact on fatty acid (FA) profiles and metabolic pathways in human Simpson-Golabi-Behmel Syndrome adipocytes and their EVs. Adipocytes were treated with 25 or 50 µM calpeptin, and EVs were isolated from conditioned media (CM) by ultracentrifugation. Immortalized human hepatocytes (IHHs) were pre-treated with 0 or 400 µM palmitic acid (PA) and subsequently exposed to CM from calpeptin-treated adipocytes. Total lipid FA composition was determined by gas chromatography–mass spectrometry, and gene expression with RNA-sequencing and qPCR, followed by univariate and multivariate statistics and pathway analyses. Calpeptin reduced EV secretion and arachidonic acid proportions in adipocytes, while also perturbing key metabolic pathways, including those of the dietarily essential polyunsaturated FAs (PUFAs). Potential biomarker candidates associated with calpeptin included C20–22 PUFAs (adipocytes) and 23:0 (EVs). Both PA and the secretome from calpeptin-treated adipocytes induced pro-inflammatory responses in IHHs. The findings suggest that calpeptin may modulate adipocyte lipid metabolism and EV secretion, with associated inflammatory responses in hepatocytes likely mediated by adipocyte‑derived secreted factors. These observations warrant further investigation into the potential adverse effects of calpeptin in the context of metabolic diseases.

We investigated the associations of pro- and anti-inflammatory fatty acids (FAs) with cartilage degradation, functional limitations, pain, and psychological well-being in knee osteoarthritis (KOA). Fasting plasma samples were obtained from controls (n = 12) and from end-stage KOA patients at baseline (n = 13), and 3 months (n = 11) and 12 months (n = 9) after knee replacement surgery. FA composition in total lipids was analyzed with gas chromatography and mass spectrometry. Cartilage loss was determined by magnetic resonance imaging, and knee pain and disability by physical performance and quantitative sensory testing, neuromuscular examination, and several questionnaires. The associations between variables were tested with the univariate analysis of variance adjusted for age and body mass index. KOA was characterized with elevated baseline 16:1n-7 percentages, while the proportions of 24:0 decreased 12 months after surgery and those of 24:1n-9 decreased 3 and 12 months after surgery. Several FA variables, such as 20:3n-6, 20:4n-6, long-chain saturated FAs, and 24:1n-9, were associated with pain, stiffness, disability, pain self-efficacy, or mental health. Circulating FAs can predict KOA symptoms, independent of age and body adiposity, and provide promising targets to design novel pain treatments.

Objective Osteoarthritis (OA) is an age-related musculoskeletal disorder lacking effective disease-modifying therapies and early diagnostic biomarkers. This study aimed to identify serum proteins that could indicate the occurrence of knee OA (KOA) and correlate with patients' pain and functional impairment.Design/Methods Fasting serum samples were collected from controls (n = 8) and patients with end-stage KOA at baseline (n = 8) and 12 months after total knee arthroplasty (n = 8). Proteomics analysis was conducted with liquid chromatography-mass spectrometry, followed by univariate and multivariate statistics and pathway analyses by MetaboAnalyst and STRING. Partial correlations were calculated with R, adjusted for sex, age, and body mass index, using a linear regression model.Results 151 proteins were upregulated and 5 proteins downregulated in baseline KOA compared to control. These proteins were linked to the complement system, immune response, coagulation, inflammatory response, calcium homeostasis, and extracellular matrix remodeling. Of these, complement factor I showed strong biomarker potential. Several proteins emerged as statistically significant predictors of cartilage loss, pain sensitivity, physical function, and corticospinal excitability. Systemic alterations persisted 12 months after surgery.Conclusion Serum proteins may serve as biomarkers of KOA, reflecting disease-related immune, inflammatory, and tissue-remodeling processes that persist after joint replacement.

Space radiation is considered the biggest threat to astronauts’ health in long-duration space missions, where the main concern is the potential carcinogenic effects from the continuous exposure to Galactic Cosmic Rays (GCR). The quality factor ( Q ) of GCR presents the greatest uncertainty, complicating accurate risk assessment and the establishment of safe radiation exposure standards for astronauts in missions beyond low Earth orbit. This study uses a recently developed analytic microdosimetric model to calculate Q values for space radiation. The influence of different target sphere diameters is examined, and optimum values are suggested. The predictions of the new model are benchmarked against experimental animal and in vitro data for RBE_max and RBE_γ -acute as well as against different versions of NASA’s model, and the International Commission on Radiological Protection (ICRP) Publication 60 recommendations. The comparisons involve quality factor values for individual ions ( Q_ion ) over the 1 MeV/u to 1 GeV/u energy range, as well as dose-averaged quality factor values for GCR ( Q _GCR ) for three space radiation environments (free space, Moon and Martian surface) and different shielding conditions (aluminium, polyethylene, and regolith of 0–20 g/cm2 ) . The results of the present model reveal strong variations of Q_ion (up to a factor of 6) and Q _GCR (up to a factor of 4) depending on the sphere diameter, with the values of 100 and 1000 nm yielding better agreement with experimental data. Interestingly, the Q _GCR values calculated for a 1,000 nm sphere diameter align with NASA’s 2012 model and ICRP Publication 60 recommendations, whereas the Q _GCR values for the 100 nm sphere diameter agree better with NASA’s most recent 2022 model.

Recent studies have shown that adipose tissue (AT) secretes elevated levels of extracellular vesicles (EVs) in obesity, and these EVs play roles in metabolic diseases. The inhibition of calpains has anti-inflammatory and anti-fibrotic effects on AT in mice and reduces EV secretion in some cell types in vitro. However, its effects on human AT and adipocyte EV secretion remain unexplored. This study aimed to investigate calpeptin's effects on EV-mediated communication and adipocyte function, offering potential insights into therapeutic approaches for metabolic diseases. Human Simpson Golabi Behmel Syndrome (SGBS) preadipocytes were differentiated and treated with calpeptin. EVs were isolated by standard ultracentrifugation, and studied by nanoparticle tracking analysis, electron microscopy, and mass spectrometry. Diverse analyses, including RNA-sequencing, liquid chromatography-mass spectrometry (LC-MS), and confocal microscopy were utilized to study calpeptin's effects on SGBS cells. AT samples from bariatric surgery patients were cultured ex vivo to assess calpeptin's effects on primary AT. We demonstrated for the first time that calpeptin reduces EV secretion in human SGBS adipocytes. Proteomic analyses revealed that calpeptin alters the abundances of proteins related to EV secretory pathways. While reduced EV secretion was accompanied by anti-inflammatory effects, calpeptin also altered insulin signalling pathways and reduced adiponectin expression, suggesting negative effects on adipocyte metabolism. Indeed, LC-MS analyses of cells and EVs revealed that calpeptin altered proteins-both in cells and EVs-that are associated with stress responses. Notably, calpeptin upregulated HO-1 in vitro and in ex vivo AT cultures, indicating induced oxidative stress in adipocytes and AT. While calpeptin shows anti-inflammatory promise in human SGBS adipocytes, its adverse effects on insulin signalling, adiponectin expression, and signs of oxidative stress raise concerns about its therapeutic potential against obesity-related pathologies in humans. Our results highlight the need to understand the broader impact of calpeptin on adipocyte metabolism.

This study investigates the capacity of near-infrared spectroscopy (NIRS) for classifying hyaluronan (HA) levels in equine synovial fluid. NIRS, combined with machine learning, discriminated between low and high HA levels with an accuracy of 81%, highlighting its potential as a promising rapid osteoarthritis diagnostic tool.

This article explores the use of microdosimetry with a silicon-on-insulator (SOI) detector for characterizing very-high-energy (VHE) heavy ion beams used specifically for single event effect (SEE) testing of electronics. The detector was deployed at CERN's heavy ion facility for radiation effects testing and exposed to lead ion beams in the 100-1000 MeV per nucleon kinetic energy range. The implications and possible benefits of using microdosimetry for SEE testing purposes are discussed.

Objective Biofluid amino acids (AAs) are potential biomarkers and therapeutic targets for knee osteoarthritis (KOA), a disease continuum of both mechanical and inflammatory aspects. Our aim was to identify AAs that would associate with cartilage degradation, subjectively and objectively assessed joint pain and function, and psychological well-being. Design Fasting blood was sampled from 8 healthy controls at baseline, and from 8 end-stage KOA patients before total knee arthroplasty and 1 year post-operatively. Plasma AA profiles were determined with high-performance liquid chromatography, and the obtained results were analyzed with univariate and multivariate statistical tests, and with pathway analysis by MetaboAnalyst. Results Cystine, β -alanine, and hydroxylysine emerged as potential biomarkers distinguishing KOA patients from controls, and several metabolic pathways were disturbed in baseline KOA. Total knee arthroplasty reduced pain and improved joint function, but the effects on plasma AA metabolism were less obvious. There were significant associations between systemic AA levels and articular cartilage thickness, KOA pain, physical performance, corticospinal excitability, and mental health, independent of age and body adiposity. Conclusion The results suggest that AA metabolism could play a role in KOA pathophysiology and motivate further studies investigating the potential of AAs as diagnostic biomarkers and therapeutic targets.

Radiation quality for determining biological effects is commonly linked to the microdosimetric quantity lineal energy ( y ) and to the dose-mean lineal energy ( y_D ). Calculations of y_D are typically performed by specialised Monte Carlo track-structure (MCTS) codes, which can be time-intensive. Thus, microdosimetry-based analytic models are potentially useful for practical calculations. Analytic model calculations of proton y_D and radiation protection quality factor ( Q ) values in sub-micron liquid water spheres (diameter 10–1000 nm) over a broad energy range (1 MeV–1 GeV) are compared against MCTS simulations by PHITS, RITRACKS, and Geant4-DNA. Additionally, an improved analytic microdosimetry model is proposed. The original analytic model of Xapsos is refined and model parameters are updated based on Geant4-DNA physics model. Direct proton energy deposition is described by an alternative energy-loss straggling distribution and the contribution of secondary electrons is calculated using the dielectric formulation of the relativistic Born approximation. MCTS simulations of proton y_D values using the latest versions of the PHITS, RITRACKS, and Geant4-DNA are reported along with the Monte Carlo Damage Simulation (MCDS) algorithm. The y_D datasets are then used within the Theory of Dual Radiation Action (TDRA) to illustrate variations in Q with proton energy. By a careful selection of parameters, overall differences at the 10 y_D are generally much lower than estimates from MCTS simulations. The differences of Q among the examined methods are somewhat smaller than those of y_D . Still, estimates of proton Q values by the present model are in better agreement with MCTS-based estimates than the existing analytic models. An improved microdosimetry-based analytic model is presented for calculating proton y_D values over a broad range of proton energies (1 MeV–1 GeV) and target sizes (10–1000 nm) in very good agreement with state-of-the-art MCTS simulations. It is envisioned that the proposed model might be used as an alternative to CPU-intensive MCTS simulations and advance practical microdosimetry and quality factor calculations in medical, accelerator, and space radiation applications.

This study investigated relationships between fatty acid (FA) profiles of extracellular vesicles (EVs) and cartilage degradation, functional limitations, pain, and psychological well-being in knee osteoarthritis (KOA). Fasting plasma was collected from controls (n = 10), end-stage KOA patients at baseline (n = 12) and at 3 and 12 months (n = 11 and 9) after joint replacement surgery, and from KOA synovial fluid (SF) at baseline (n = 10). EVs were isolated with the exoEasy Maxi Kit or size-exclusion chromatography, and EV FAs were analyzed with gas chromatography-mass spectrometry. Articular cartilage loss was determined by magnetic resonance imaging, and knee pain and function were assessed through questionnaires and physiatric and neuromuscular examinations. The associations of these data with EV FA proportions were tested with the univariate analysis of variance adjusted for age and body adiposity. Higher proportions of 16:1n-7, 18:1n-7, and total monounsaturated FAs in plasma EVs were associated with less severe KOA symptoms, while higher 24:1n-9, total saturated FAs, and ratios of arachidonic acid to long-chain n-3 polyunsaturated FAs (PUFAs) were linked to KOA pain, independent of age and body adiposity. In SF EVs, higher product/precursor ratios of n-6 PUFAs were associated with increased joint stiffness, and higher total dimethyl acetals were linked to physical disability. EV FAs emerged as significant indicators of knee pain and function. The results can be utilized to discover novel biomarkers for KOA and may have implications for targeted prevention and treatment of KOA symptoms by using EVs with a specific FA cargo.

The discrete physics models available in the Geant4-DNA Monte Carlo toolkit are a subject of continuous evolution and improvement in order to meet the needs of state-of-the-art radiobiological research for medical and space applications. The current capabilities of Geant4-DNA for event-by-event electron transport extend up to 1 MeV. In this work, Geant4-DNA’s most accurate electron inelastic model for sub-keV energies is improved and extended up to 10 MeV via the Relativistic Plane Wave Born Approximation and other theoretical considerations. Benchmark simulations of the electronic stopping power and range of electrons in liquid water using the new model show almost excellent agreement (at the few % level) with the recommendations of the International Commission on Radiation Units and Measurements (ICRU) up to 10 MeV, offering notable improvement (by a factor of ~2) over the default Geant4-DNA inelastic model and an order-of-magnitude higher electron limit. The present development will allow Geant4-DNA users to perform electron track-structure simulations up to 10 MeV, thus, covering a wider range of radiotherapeutic applications (including FLASH-RT) as well as space applications involving MeV electrons which are not currently reachable.

Fully fragmented, very-high-energy (VHE) heavy-ion beams offer interesting possibilities for radiation hardness assurance testing of electronic components exposed to the Galactic Cosmic Ray (GCR) space environment. In this article, we perform the dosimetry of these fully fragmented ion beams through a combination of silicon solid-state detector measurements and detailed Monte Carlo (MC) simulations in FLUKA focusing on the interaction between the beam and the device under test. The tested experimental configurations highlight the challenges of implementing this method in VHE ion facilities. The MC simulations offer further insights into the optimization of this approach.

The RADiation–hard Electron Monitor (RADEM) is an instrument on board the ESA JUpiter ICy moons Explorer (JUICE) deep-space mission launched on April 14th, 2023. As a part of the Cosmic Vision program, RADEM on JUICE will spend over three years exploring the radiation environment of the Jovian system, including its icy moons Ganymede, Callisto, and Europa. The instrument serves as an on-board radiation monitor, providing nonstop information on particle fluxes and their energy spectra. In addition to being a platform subsystem relevant to spacecraft safety and health, RADEM obtains scientifically valuable data on the radiation environment and extends the particle detection range covered by the JUICE Particle Environment Package (PEP) instrument suite to much higher energies, and broadens the energy coverage in the tens to hundreds of MeV range for electrons and protons, compared to past missions. RADEM consists of three detector subunits: the Electron Detector Head, the Proton Heavy Ion Detector Head, and the Directional Detector Head. Each of them is connected to a separate readout electronics with a dedicated front-end Application–Specific Integrated Circuit (ASIC) designed especially for the JUICE mission. RADEM measures electrons in the 0.3–40 MeV energy range, protons in the 5–250 MeV energy range, and heavy ions within the Linear Energy Transfer range from 0.1 to 10 MeV cm mg−1. The Directional Detector provides an angular coverage of incoming radiation up to about 35

Osteoarthritis (OA) and autoimmune-driven rheumatoid arthritis (RA) are inflammatory joint diseases that share partly similar symptoms but have different, inadequately understood pathogeneses. Adipose tissues, including intra-articular infrapatellar fat pad (IFP), may contribute to their development. Analysis of differentially expressed genes (DEGs) in IFPs could improve the diagnostics of these conditions and help to develop novel treatment strategies. The aim was to identify potentially crucial genes and pathways discriminating OA and RA IFPs using RNA sequencing analysis. We aimed to distinguish genetically distinct patient groups as a starting point for further translational studies with the eventual goal of personalized medicine. Samples were collected from arthritic knees during total knee arthroplasty of sex- and age-matched OA and seropositive RA patients (n=5-6/group). Metabolic pathways of interest were investigated by whole transcriptome sequencing, and DEGs were analyzed with univariate tests, hierarchical clustering (HC), and pathway analyses. There was significant interindividual variation in mRNA expression patterns, but distinct subgroups of OA and RA patients emerged that reacted similarly to their disease states based on HC. Compared to OA, RA samples showed 703 genes to be upregulated and 691 genes to be downregulated. Signaling pathway analyses indicated that these DEGs had common pathways in lipid metabolism, fatty acid biosynthesis and degradation, adipocytokine and insulin signaling, inflammatory response, and extracellular matrix organization. The divergent mRNA expression profiles in RA and OA suggest contribution of IFP to the regulation of synovial inflammatory processes and articular cartilage degradation and could provide novel diagnostic and therapeutic targets.

OBJECTIVE:To develop and assess an automatic and robust knee musculoskeletal finite element (MSK-FE) modeling pipeline. METHODS:Magnetic resonance images (MRIs) were used to train nnU-Net networks for auto-segmentation of knee bones (femur, tibia, patella, and fibula), cartilages (femur, tibia, and patella), menisci, and major knee ligaments. Two different MRI sequences were used to broaden applicability. Next, we created MSK-FE models of an unseen dataset using two MSK-FE modeling pipelines: template-based and auto-meshing. MSK models had personalized knee geometries with multi-degree-of-freedom elastic foundation contacts. FE models used fibril-reinforced poroviscoelastic swelling material models for cartilages and menisci. RESULTS:Volumes of knee bones, cartilages, and menisci did not significantly differ (p>0.05) across MRI sequences. MSK models estimated secondary knee kinematics during passive knee flexion tests consistent with in vivo and simulation-based values from the literature. Between the template-based and auto-meshing FE models, estimated cartilage mechanics often differed significantly (p<0.05), though differences were <15% (considering peaks during walking), i.e., <1.5 MPa for maximum principal stress, <1 percentage point for collagen fibril strain, and <3 percentage points for maximum shear strain. CONCLUSION:The template-based modeling provided a more rapid and robust tool than the auto-meshing approach, while the estimated knee biomechanics were comparable. Nonetheless, the auto-meshing approach might provide more accurate estimates in subjects with distinct knee irregularities, e.g., cartilage lesions. SIGNIFICANCE:The MSK-FE modeling tool provides a rapid, easy-to-use, and robust approach for investigating task- and person-specific mechanical responses of the knee cartilage and menisci, holding significant promise, e.g., in personalized rehabilitation planning.

Abstract Background Obesity is a worldwide epidemic characterized by adipose tissue (AT) inflammation. AT is also a source of extracellular vesicles (EVs) that have recently been implicated in disorders related to metabolic syndrome. However, our understanding of mechanistic aspect of obesity’s impact on EV secretion from human AT remains limited. Methods We investigated EVs from human Simpson Golabi Behmel Syndrome (SGBS) adipocytes, and from AT as well as plasma of subjects undergoing bariatric surgery. SGBS cells were treated with TNFα, palmitic acid, and eicosapentaenoic acid. Various analyses, including nanoparticle tracking analysis, electron microscopy, high-resolution confocal microscopy, and gas chromatography–mass spectrometry, were utilized to study EVs. Plasma EVs were analyzed with imaging flow cytometry. Results EVs from mature SGBS cells differed significantly in size and quantity compared to preadipocytes, disagreeing with previous findings in mouse adipocytes and indicating that adipogenesis promotes EV secretion in human adipocytes. Inflammatory stimuli also induced EV secretion, and altered EV fatty acid (FA) profiles more than those of cells, suggesting the role of EVs as rapid responders to metabolic shifts. Visceral AT (VAT) exhibited higher EV secretion compared to subcutaneous AT (SAT), with VAT EV counts positively correlating with plasma triacylglycerol (TAG) levels. Notably, the plasma EVs of subjects with obesity contained a higher number of adiponectin-positive EVs than those of lean subjects, further demonstrating higher AT EV secretion in obesity. Moreover, plasma EV counts of people with obesity positively correlated with body mass index and TNF expression in SAT, connecting increased EV secretion with AT expansion and inflammation. Finally, EVs from SGBS adipocytes and AT contained TAGs, and EV secretion increased despite signs of less active lipolytic pathways, indicating that AT EVs could be involved in the mobilization of excess lipids into circulation. Conclusions We are the first to provide detailed FA profiles of human AT EVs. We report that AT EV secretion increases in human obesity, implicating their role in TAG transport and association with adverse metabolic parameters, thereby emphasizing their role in metabolic disorders. These findings promote our understanding of the roles that EVs play in human AT biology and metabolic disorders.

Objective Hyaluronic acid (HA) in synovial fluid (SF) contributes to boundary lubrication with altered levels in osteoarthritis (OA) and rheumatoid arthritis (RA). SF extracellular vesicles (EVs) may participate in arthritis by affecting inflammation and cartilage degradation. It remains unknown whether HA and EVs display joint-specific alterations in arthritic SFs. Design We investigated the numbers and characteristics of HA-particles and large EVs in SF from knees and shoulders of 8 OA and 8 RA patients and 8 trauma controls, and in plasma from 10 healthy controls and 11 knee OA patients. The plasma and SF HA concentrations were determined with a sandwich-type enzyme-linked sorbent assay, and EVs and HA-particles were characterized from plasma and unprocessed and centrifuged SFs with confocal microscopy. The data were compared according to diagnosis, location, and preanalytical processing. Results The main findings were: (1) OA and RA SFs can be distinguished from trauma joints based on the distinctive profiles of HA-particles and large EVs, (2) there are differences in the SF HA and EV characteristics between shoulder and knee joints that could reflect their dissimilar mobility, weight-bearing, and shock absorption properties, (3) EV counts in SF and plasma can positively associate with pain parameters independent of age and body adiposity, and (4) low-speed centrifugation causes alterations in the features of HA-particles and EVs, complicating their examination in the original state. Conclusions Arthritis and anatomical location can affect the characteristics of HA-particles and large EVs that may have potential as biomarkers and effectors in joint degradation and pain.