Trained immunity is regulated by T cell-induced CD40-TRAF6 signaling.

Trained immunity is characterized by histone modifications and metabolic changes in innate immune cells following exposure to inflammatory signals, leading to heightened responsiveness to secondary stimuli. Although our understanding of the molecular regulation of trained immunity has increased, the role of adaptive immune cells herein remains largely unknown. Here, we show that T cells modulate trained immunity via cluster of differentiation 40-tissue necrosis factor receptor-associated factor 6 (CD40-TRAF6) signaling. CD40-TRAF6 inhibition modulates functional, transcriptomic, and metabolic reprogramming and modifies histone 3 lysine 4 trimethylation associated with trained immunity. Besides in vitro studies, we reveal that single-nucleotide polymorphisms in the proximity of CD40 are linked to trained immunity responses in vivo and that combining CD40-TRAF6 inhibition with cytotoxic T lymphocyte antigen 4-immunoglobulin (CTLA4-Ig)-mediated co-stimulatory blockade induces long-term graft acceptance in a murine heart transplantation model. Combined, our results reveal that trained immunity is modulated by CD40-TRAF6 signaling between myeloid and adaptive immune cells and that this can be leveraged for therapeutic purposes.

Polymersomes with splenic avidity target red pulp myeloid cells for cancer immunotherapy.

Regulating innate immunity is an emerging approach to improve cancer immunotherapy. Such regulation requires engaging myeloid cells by delivering immunomodulatory compounds to hematopoietic organs, including the spleen. Here we present a polymersome-based nanocarrier with splenic avidity and propensity for red pulp myeloid cell uptake. We characterized the in vivo behaviour of four chemically identical yet topologically different polymersomes by in vivo positron emission tomography imaging and innovative flow and mass cytometry techniques. Upon intravenous administration, relatively large and spherical polymersomes accumulated rapidly in the spleen and efficiently targeted myeloid cells in the splenic red pulp. When loaded with ß-glucan, intravenously administered polymersomes significantly reduced tumour growth in a mouse melanoma model. We initiated our nanotherapeutic's clinical translation with a biodistribution study in non-human primates, which revealed that the platform's splenic avidity is preserved across species.

Cutting Edge: Hepatic Stellate Cells Drive the Phenotype of Monocyte-derived Macrophages to Regulate Liver Fibrosis in Metabolic Dysfunction-associated Steatohepatitis.

Metabolic dysfunction-associated steatohepatitis (MASH) is characterized by infiltration of monocyte-derived macrophages (MdMs) into the liver; however, the function of these macrophages is largely unknown. We previously demonstrated that a population of MdMs, referred to as hepatic lipid-associated macrophages (LAMs), assemble into aggregates termed hepatic crown-like structures in areas of liver fibrosis. Intriguingly, decreasing MdM recruitment resulted in increased liver fibrosis, suggesting that LAMs contribute to antifibrotic pathways in MASH. In this study, we determined that hepatic crown-like structures are characterized by intimate interactions between activated hepatic stellate cells (HSCs) and macrophages in a collagen matrix in a mouse model of MASH. MASH macrophages displayed collagen-degrading capacities, and HSCs derived from MASH livers promoted expression of LAM marker genes and acquisition of a collagen-degrading phenotype in naive macrophages. These data suggest that crosstalk between HSCs and macrophages may contribute to collagen degradation MASH.

Modifiable risk factors for mild cognitive impairment among cognitively normal community-dwelling older adults: A systematic review and meta-analysis.

Although numerous studies have investigated modifiable risk factors for mild cognitive impairment (MCI) among community-dwelling seniors, no meta-analysis has summarized these findings. Five databases were searched from January 1, 2000, to December 30, 2023. The protocol was registered with PROSPERO. Data were extracted and reported following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Relevant meta-analyses of modifiable risk factors were performed. The evidence of each factor was assessed by the GRADE for cohort studies. Of 16,651 citations, 87 studies involving 225,584 community-dwelling seniors were included. Fourteen meta-analyses involving 20 studies with 44,199 participants were performed. The analyses revealed low-to-moderate-quality evidence supporting that diabetes, 2 or more comorbidities, anxiety, apathy, depressive symptoms, and physical frailty were risk factors for incident MCI in older adults. Conversely, hypertension, agitation, and irritability might not be risk factors. Additionally, moderate-quality evidence supports the protective effect of engaging in cognitive-demanding activities on the onset of MCI. Collectively, this study constitutes the first extensive compilation of evidence regarding the various risk factors for the development of MCI in older adults. Our findings hold significant potential to guide the formulation of prevention and management strategies to either prevent or potentially reverse the onset of MCI.

Brain age as a biomarker for pathological versus healthy ageing - a REMEMBER study.

OBJECTIVES: This study aimed to evaluate the potential clinical value of a new brain age prediction model as a single interpretable variable representing the condition of our brain. Among many clinical use cases, brain age could be a novel outcome measure to assess the preventive effect of life-style interventions. METHODS: The REMEMBER study population (N = 742) consisted of cognitively healthy (HC,N = 91), subjective cognitive decline (SCD,N = 65), mild cognitive impairment (MCI,N = 319) and AD dementia (ADD,N = 267) subjects. Automated brain volumetry of global, cortical, and subcortical brain structures computed by the CE-labeled and FDA-cleared software icobrain dm (dementia) was retrospectively extracted from T1-weighted MRI sequences that were acquired during clinical routine at participating memory clinics from the Belgian Dementia Council. The volumetric features, along with sex, were combined into a weighted sum using a linear model, and were used to predict 'brain age' and 'brain predicted age difference' (BPAD = brain age-chronological age) for every subject. RESULTS: MCI and ADD patients showed an increased brain age compared to their chronological age. Overall, brain age outperformed BPAD and chronological age in terms of classification accuracy across the AD spectrum. There was a weak-to-moderate correlation between total MMSE score and both brain age (r = -0.38,p < .001) and BPAD (r = -0.26,p < .001). Noticeable trends, but no significant correlations, were found between BPAD and incidence of conversion from MCI to ADD, nor between BPAD and conversion time from MCI to ADD. BPAD was increased in heavy alcohol drinkers compared to non-/sporadic (p = .014) and moderate (p = .040) drinkers. CONCLUSIONS: Brain age and associated BPAD have the potential to serve as indicators for, and to evaluate the impact of lifestyle modifications or interventions on, brain health.

Targeting F-actin stress fibers to suppress the dedifferentiated phenotype in chondrocytes.

Actin is a central mediator of the chondrocyte phenotype. Monolayer expansion of articular chondrocytes on tissue culture polystyrene, for cell-based repair therapies, leads to chondrocyte dedifferentiation. During dedifferentiation, chondrocytes spread and filamentous (F-)actin reorganizes from a cortical to a stress fiber arrangement causing a reduction in cartilage matrix expression and an increase in fibroblastic matrix and contractile molecule expression. While the downstream mechanisms regulating chondrocyte molecular expression by alterations in F-actin organization have become elucidated, the critical upstream regulators of F-actin networks in chondrocytes are not completely known. Tropomyosin (TPM) and the RhoGTPases are known regulators of F-actin networks. The main purpose of this study is to elucidate the regulation of passaged chondrocyte F-actin stress fiber networks and cell phenotype by the specific TPM, TPM3.1, and the RhoGTPase, CDC42. Our results demonstrated that TPM3.1 associates with cortical F-actin and stress fiber F-actin in primary and passaged chondrocytes, respectively. In passaged cells, we found that pharmacological TPM3.1 inhibition or siRNA knockdown causes F-actin reorganization from stress fibers back to cortical F-actin and causes an increase in G/F-actin. CDC42 inhibition also causes formation of cortical F-actin. However, pharmacological CDC42 inhibition, but not TPM3.1 inhibition, leads to the re-association of TPM3.1 with cortical F-actin. Both TPM3.1 and CDC42 inhibition, as well as TPM3.1 knockdown, reduces nuclear localization of myocardin related transcription factor, which suppresses dedifferentiated molecule expression. We confirmed that TPM3.1 or CDC42 inhibition partially redifferentiates passaged cells by reducing fibroblast matrix and contractile expression, and increasing chondrogenic SOX9 expression. A further understanding on the regulation of F-actin in passaged cells may lead into new insights to stimulate cartilage matrix expression in cells for regenerative therapies.

Cortico-limbic interactions and carotid atherosclerotic burden during chronic stress exposure.

BACKGROUND AND AIMS: Chronic stress associates with cardiovascular disease, but mechanisms remain incompletely defined. Advanced imaging was used to identify stress-related neural imaging phenotypes associated with atherosclerosis. METHODS: Twenty-seven individuals with post-traumatic stress disorder (PTSD), 45 trauma-exposed controls without PTSD, and 22 healthy controls underwent 18F-fluorodeoxyglucose positron emission tomography/magnetic resonance imaging (18F-FDG PET/MRI). Atherosclerotic inflammation and burden were assessed using 18F-FDG PET (as maximal target-to-background ratio, TBR max) and MRI, respectively. Inflammation was assessed using high-sensitivity C-reactive protein (hsCRP) and leucopoietic imaging (18F-FDG PET uptake in spleen and bone marrow). Stress-associated neural network activity (SNA) was assessed on 18F-FDG PET as amygdala relative to ventromedial prefrontal cortex (vmPFC) activity. MRI diffusion tensor imaging assessed the axonal integrity (AI) of the uncinate fasciculus (major white matter tract connecting vmPFC and amygdala). RESULTS: Median age was 37 years old and 54% of participants were female. There were no significant differences in atherosclerotic inflammation between participants with PTSD and controls; adjusted mean difference in TBR max (95% confidence interval) of the aorta 0.020 (-0.098, 0.138), and of the carotids 0.014 (-0.091, 0.119). Participants with PTSD had higher hsCRP, spleen activity, and aorta atherosclerotic burden (normalized wall index). Participants with PTSD also had higher SNA and lower AI. Across the cohort, carotid atherosclerotic burden (standard deviation of wall thickness) associated positively with SNA and negatively with AI independent of Framingham risk score. CONCLUSIONS: In this study of limited size, participants with PTSD did not have higher atherosclerotic inflammation than controls. Notably, impaired cortico-limbic interactions (higher amygdala relative to vmPFC activity or disruption of their intercommunication) associated with carotid atherosclerotic burden. Larger studies are needed to refine these findings.

Macrophage PET imaging in mouse models of cardiovascular disease and cancer with an apolipoprotein-inspired radiotracer.

Macrophages are key inflammatory mediators in many pathological conditions, including cardiovascular disease (CVD) and cancer, the leading causes of morbidity and mortality worldwide. This makes macrophage burden a valuable diagnostic marker and several strategies to monitor these cells have been reported. However, such strategies are often high-priced, non-specific, invasive, and/or not quantitative. Here, we developed a positron emission tomography (PET) radiotracer based on apolipoprotein A1 (ApoA1), the main protein component of high-density lipoprotein (HDL), which has an inherent affinity for macrophages. We radiolabeled an ApoA1-mimetic peptide (mA1) with zirconium-89 (89Zr) to generate a lipoprotein-avid PET probe (89Zr-mA1). We first characterized 89Zr-mA1's affinity for lipoproteins in vitro by size exclusion chromatography. To study 89Zr-mA1's in vivo behavior and interaction with endogenous lipoproteins, we performed extensive studies in wildtype C57BL/6 and Apoe-/- hypercholesterolemic mice. Subsequently, we used in vivo PET imaging to study macrophages in melanoma and myocardial infarction using mouse models. The tracer's cell specificity was assessed by histology and mass cytometry (CyTOF). Our data show that 89Zr-mA1 associates with lipoproteins in vitro. This is in line with our in vivo experiments, in which we observed longer 89Zr-mA1 circulation times in hypercholesterolemic mice compared to C57BL/6 controls. 89Zr-mA1 displayed a tissue distribution profile similar to ApoA1 and HDL, with high kidney and liver uptake as well as substantial signal in the bone marrow and spleen. The tracer also accumulated in tumors of melanoma-bearing mice and in the ischemic myocardium of infarcted animals. In these sites, CyTOF analyses revealed that natZr-mA1 was predominantly taken up by macrophages. Our results demonstrate that 89Zr-mA1 associates with lipoproteins and hence accumulates in macrophages in vivo. 89Zr-mA1's high uptake in these cells makes it a promising radiotracer for non-invasively and quantitatively studying conditions characterized by marked changes in macrophage burden.

Uncovering atherosclerotic cardiovascular disease by PET imaging.

Assessing atherosclerosis severity is essential for precise patient stratification. Specifically, there is a need to identify patients with residual inflammation because these patients remain at high risk of cardiovascular events despite optimal management of cardiovascular risk factors. Molecular imaging techniques, such as PET, can have an essential role in this context. PET imaging can indicate tissue-based disease status, detect early molecular changes and provide whole-body information. Advances in molecular biology and bioinformatics continue to help to decipher the complex pathogenesis of atherosclerosis and inform the development of imaging tracers. Concomitant advances in tracer synthesis methods and PET imaging technology provide future possibilities for atherosclerosis imaging. In this Review, we summarize the latest developments in PET imaging techniques and technologies for assessment of atherosclerotic cardiovascular disease and discuss the relationship between imaging readouts and transcriptomics-based plaque phenotyping.

Steric Effects on the Photovoltaic Performance of Panchromatic Ruthenium Sensitizers for Dye-Sensitized Solar Cells.

Three new heteroleptic Ru complexes, CYC-B22, CYC-B23C, and CYC-B23T, were prepared as sensitizers for coadsorbent-free, panchromatic, and efficient dye-sensitized solar cells. They are simultaneously functionalized with highly conjugated anchoring and ancillary ligands to explore the electronic and steric effects on their photovoltaic characteristics. The coadsorbent-free device based on CYC-B22 achieved the best power conversion efficiency (PCE) of 8.63% and a panchromatic response extending to 850 nm. The two stereoisomers, CYC-B23C and CYC-B23T coordinated with an unsymmetrical anchoring ligand, display similar absorption properties and the same driving forces for electron injection as well as dye regeneration. Nevertheless, the devices show not only the remarkably distinct PCE (6.64% vs 8.38%) but also discernible stability. The molecular simulation for the two stereoisomers adsorbed on TiO2 clarifies the distinguishable distances (16.9 Å vs 19.0 Å) between the sulfur atoms in the NCS ligands and the surface of the TiO2, dominating the charge recombination dynamics and iodine binding and therefore the PCE and stability of the devices. This study on the steric effects caused by the highly conjugated and unsymmetrical anchoring ligand on the adsorption geometry and photovoltaic performance of the dyes paves a new way for advancing the molecular design of polypyridyl metal complex sensitizers.

From Promise to Practice: How Health Researchers Understand and Promote Transdisciplinary Collaboration.

There is an increasing emphasis on transdisciplinary research to address the complex challenges faced by health systems. However, research has not adequately explored how members of transdisciplinary research teams perceive, understand, and promote transdisciplinary collaboration. As such, there is a need to investigate collaborative behaviors, knowledge, and the impacts of transdisciplinary research. To address this gap, we conducted a longitudinal realist evaluation of transdisciplinary collaboration within a 5-year National Health and Medical Research Council-funded Center of Research Excellence in Transdisciplinary Frailty Research. The current study aimed to explore researchers' perceptions and promotion of transdisciplinary research specifically within the context of frailty research using qualitative methods. Participants described transdisciplinary research as a collaborative and integrative approach that involves individuals from various disciplines working together to tackle complex research problems. However, participants often used terms like interdisciplinary and multidisciplinary interchangeably, indicating that a shared understanding of transdisciplinary research is needed. Barriers to transdisciplinary collaboration included time constraints, geographical distance, and entrenched collaboration patterns. To overcome these challenges, participants suggested implementing strategies such as creating a shared vision and goals, establishing appropriate collaboration systems and structures, and role modeling collaborative behaviors, values, and attitudes. Our findings underscore the need for practical knowledge in developing transdisciplinary collaboration and leadership skills across different career stages. In the absence of formal training, sustained and immersive programs that connect researchers with peers, educators, and role models from various disciplines and provide experiential learning opportunities, may be valuable in fostering successful transdisciplinary collaboration.

Towards validation in clinical routine: a comparative analysis of visual MTA ratings versus the automated ratio between inferior lateral ventricle and hippocampal volumes in Alzheimer's disease diagnosis.

PURPOSE: To assess the performance of the inferior lateral ventricle (ILV) to hippocampal (Hip) volume ratio on brain MRI, for Alzheimer's disease (AD) diagnostics, comparing it to individual automated ILV and hippocampal volumes, and visual medial temporal lobe atrophy (MTA) consensus ratings. METHODS: One-hundred-twelve subjects (mean age ± SD, 66.85 ± 13.64 years) with varying degrees of cognitive decline underwent MRI using a Philips Ingenia 3T. The MTA scale by Scheltens, rated on coronal 3D T1-weighted images, was determined by three experienced radiologists, blinded to diagnosis and sex. Automated volumetry was computed by icobrain dm (v. 5.10) for total, left, right hippocampal, and ILV volumes. The ILV/Hip ratio, defined as the percentage ratio between ILV and hippocampal volumes, was calculated and compared against a normative reference population (n = 1903). Inter-rater agreement, association, classification accuracy, and clinical interpretability on patient level were reported. RESULTS: Visual MTA scores showed excellent inter-rater agreement. Ordinal logistic regression and correlation analyses demonstrated robust associations between automated brain segmentations and visual MTA ratings, with the ILV/Hip ratio consistently outperforming individual hippocampal and ILV volumes. Pairwise classification accuracy showed good performance without statistically significant differences between the ILV/Hip ratio and visual MTA across disease stages, indicating potential interchangeability. Comparison to the normative population and clinical interpretability assessments showed commensurability in classifying MTA "severity" between visual MTA and ILV/Hip ratio measurements. CONCLUSION: The ILV/Hip ratio shows the highest correlation to visual MTA, in comparison to automated individual ILV and hippocampal volumes, offering standardized measures for diagnostic support in different stages of cognitive decline.

Confidence as a metacognitive contributor to and consequence of misinformation experiences.

Exposures to inaccurate information can lead people to become confused about what is true, to doubt their understandings, and to rely on the ideas later. Recent work has begun to investigate the role of metacognition in these effects. We review research foregrounding confidence as an exemplar metacognitive contributor to misinformation experiences. Miscalibrations between confidence about what one knows, and the actual knowledge one possesses, can help explain why people might hold fast to misinformed beliefs even in the face of counterevidence. Miscalibrations can also emerge after brief exposures to new misinformation, allowing even obvious inaccuracies to influence subsequent performance. Evidence additionally suggests confidence may present a useful target for intervention, helping to encourage careful evaluation under the right conditions.

Human serous cavity macrophages and dendritic cells possess counterparts in the mouse with a distinct distribution between species.

In mouse peritoneal and other serous cavities, the transcription factor GATA6 drives the identity of the major cavity resident population of macrophages, with a smaller subset of cavity-resident macrophages dependent on the transcription factor IRF4. Here we showed that GATA6+ macrophages in the human peritoneum were rare, regardless of age. Instead, more human peritoneal macrophages aligned with mouse CD206+ LYVE1+ cavity macrophages that represent a differentiation stage just preceding expression of GATA6. A low abundance of CD206+ macrophages was retained in C57BL/6J mice fed a high-fat diet and in wild-captured mice, suggesting that differences between serous cavity-resident macrophages in humans and mice were not environmental. IRF4-dependent mouse serous cavity macrophages aligned closely with human CD1c+CD14+CD64+ peritoneal cells, which, in turn, resembled human peritoneal CD1c+CD14-CD64- cDC2. Thus, major populations of serous cavity-resident mononuclear phagocytes in humans and mice shared common features, but the proportions of different macrophage differentiation stages greatly differ between the two species, and dendritic cell (DC2)-like cells were especially prominent in humans.

Targeting F-actin stress fibers to suppress the dedifferentiated phenotype in chondrocytes.

Actin is a central mediator of the chondrocyte phenotype. Monolayer expansion of articular chondrocytes on tissue culture polystyrene, for cell-based repair therapies, leads to chondrocyte dedifferentiation. During dedifferentiation, chondrocytes spread and filamentous (F-)actin reorganizes from a cortical to a stress fiber arrangement causing a reduction in cartilage matrix expression and an increase in fibroblastic matrix and contractile molecule expression. While the downstream mechanisms regulating chondrocyte molecular expression by alterations in F-actin organization have become elucidated, the critical upstream regulators of F-actin networks in chondrocytes are not completely known. Tropomyosin (TPM) and the RhoGTPases are known regulators of F-actin networks. The purpose of this study is to elucidate the regulation of passaged chondrocyte F-actin stress fiber networks and cell phenotype by the specific TPM, TPM3.1, and the RhoGTPase, CDC42. Our results demonstrated that TPM3.1 associates with cortical F-actin and stress fiber F-actin in primary and passaged chondrocytes, respectively. In passaged cells, we found that TPM3.1 inhibition causes F-actin reorganization from stress fibers back to cortical F-actin and also causes an increase in G/F-actin. CDC42 inhibition also causes formation of cortical F-actin. However, CDC42 inhibition, but not TPM3.1 inhibition, leads to the re-association of TPM3.1 with cortical F-actin. Both TPM3.1 and CDC42 inhibition reduces nuclear localization of myocardin related transcription factor, which is known to suppress dedifferentiated molecule expression. We confirmed that TPM3.1 or CDC42 inhibition partially redifferentiates passaged cells by reducing fibroblast matrix and contractile expression, and increasing chondrogenic SOX9 expression. A further understanding on the regulation of F-actin in passaged cells may lead into new insights to stimulate cartilage matrix expression in cells for regenerative therapies.

CSF biomarker analysis of ABCA7 mutation carriers suggests altered APP processing and reduced inflammatory response.

BACKGROUND: The Alzheimer's disease (AD) risk gene ABCA7 has suggested functions in lipid metabolism and the immune system. Rare premature termination codon (PTC) mutations and an expansion of a variable number of tandem repeats (VNTR) polymorphism in the gene, both likely cause a lower ABCA7 expression and hereby increased risk for AD. However, the exact mechanism of action remains unclear. By studying CSF biomarkers reflecting different types of AD-related pathological processes, we aim to get a better insight in those processes and establish a biomarker profile of mutation carriers. METHODS: The study population consisted of 229 AD patients for whom CSF was available and ABCA7 sequencing and VNTR genotyping had been performed. This included 28 PTC mutation and 16 pathogenic expansion carriers. CSF levels of Aß1-42, Aß1-40, P-tau181, T-tau, sAPPα, sAPPß, YKL-40, and hFABP were determined using ELISA and Meso Scale Discovery assays. We compared differences in levels of these biomarkers and the Aß ratio between AD patients with or without an ABCA7 PTC mutation or expansion using linear regression on INT-transformed data with APOE-status, age and sex as covariates. RESULTS: Carriers of ABCA7 expansion mutations had significantly lower Aß1-42 levels (P = 0.022) compared with non-carrier patients. The effect of the presence of ABCA7 mutations on CSF levels was especially pronounced in APOE ε4-negative carriers. In addition, VNTR expansion carriers had reduced Aß1-40 (P = 0.023), sAPPα (P = 0.047), sAPPß (P = 0.016), and YKL-40 (P = 0.0036) levels. CONCLUSIONS: Our results are suggestive for an effect on APP processing by repeat expansions given the changes in the amyloid-related CSF biomarkers that were found in carriers. The decrease in YKL-40 levels in expansion carriers moreover suggests that these patients potentially have a reduced inflammatory response to AD damage. Moreover, our findings suggest the existence of a mechanism, independent of lowered expression, affecting neuropathology in expansion carriers.

Acid ceramidase regulates innate immune memory.

Innate immune memory, also called "trained immunity," is a functional state of myeloid cells enabling enhanced immune responses. This phenomenon is important for host defense, but also plays a role in various immune-mediated conditions. We show that exogenously administered sphingolipids and inhibition of sphingolipid metabolizing enzymes modulate trained immunity. In particular, we reveal that acid ceramidase, an enzyme that converts ceramide to sphingosine, is a potent regulator of trained immunity. We show that acid ceramidase regulates the transcription of histone-modifying enzymes, resulting in profound changes in histone 3 lysine 27 acetylation and histone 3 lysine 4 trimethylation. We confirm our findings by identifying single-nucleotide polymorphisms in the region of ASAH1, the gene encoding acid ceramidase, that are associated with the trained immunity cytokine response. Our findings reveal an immunomodulatory effect of sphingolipids and identify acid ceramidase as a relevant therapeutic target to modulate trained immunity responses in innate immune-driven disorders.

Steatosis drives monocyte-derived macrophage accumulation in human metabolic dysfunction-associated fatty liver disease.

Background & Aims: Metabolic dysfunction-associated fatty liver disease (MAFLD) is a common complication of obesity with a hallmark feature of hepatic steatosis. Recent data from animal models of MAFLD have demonstrated substantial changes in macrophage composition in the fatty liver. In humans, the relationship between liver macrophage heterogeneity and liver steatosis is less clear. Methods: Liver tissue from 21 participants was collected at time of bariatric surgery and analysed using flow cytometry, immunofluorescence, and H&E microscopy. Single-cell RNA sequencing was also conducted on a subset of samples (n = 3). Intrahepatic triglyceride content was assessed via MRI and tissue histology. Mouse models of hepatic steatosis were used to investigate observations made from human liver tissue. Results: We observed variable degrees of liver steatosis with minimal fibrosis in our participants. Single-cell RNA sequencing revealed four macrophage clusters that exist in the human fatty liver encompassing Kupffer cells and monocyte-derived macrophages (MdMs). The genes expressed in these macrophage subsets were similar to those observed in mouse models of MAFLD. Hepatic CD14+ monocyte/macrophage number correlated with the degree of steatosis. Using mouse models of early liver steatosis, we demonstrate that recruitment of MdMs precedes Kupffer cell loss and liver damage. Electron microscopy of isolated macrophages revealed increased lipid accumulation in MdMs, and ex vivo lipid transfer experiments suggested that MdMs may serve a distinct role in lipid uptake during MAFLD. Conclusions: The human liver in MAFLD contains macrophage subsets that align well with those that appear in mouse models of fatty liver disease. Recruited myeloid cells correlate well with the degree of liver steatosis in humans. MdMs appear to participate in lipid uptake during early stages of MALFD. Impact and implications: Metabolic dysfunction associated fatty liver disease (MAFLD) is extremely common; however, the early inflammatory responses that occur in human disease are not well understood. In this study, we investigated macrophage heterogeneity in human livers during early MAFLD and demonstrated that similar shifts in macrophage subsets occur in human disease that are similar to those seen in preclinical models. These findings are important as they establish a translational link between mouse and human models of disease, which is important for the development and testing of new therapeutic approaches for MAFLD.

My Wellbeing Journal: Development of a communication and goal-setting tool to improve care for older adults with chronic conditions and multimorbidity.

BACKGROUND: Chronic conditions and multimorbidity, the presence of two or more chronic conditions, are increasingly common in older adults. Effective management of chronic conditions and multimorbidity in older adults requires a collaborative and person-centred approach that considers the individual's goals, preferences and priorities. However, ensuring high-quality personalised care for older adults with multimorbidity can be challenging due to the complexity of their care needs, limited time and a lack of patient preparation to discuss their personal goals and preferences with their healthcare team. OBJECTIVE: To codesign a communication and goal-setting tool, My Wellbeing Journal, to support personalised care planning for older adults with chronic conditions and multimorbidity. DESIGN: We drew on an experience-based codesign approach to develop My Wellbeing Journal. This article reports on the final end-user feedback, which was collected via an online survey with older adults and their carers. SETTING AND PARTICIPANTS: Older adults with chronic conditions, multimorbidity and informal carers living in Australia. Personalised care planning was considered in the context of primary care. RESULTS: A total of 88 participants completed the online survey. The survey focused on participants' feedback on the tool in terms of effectiveness, efficiency, satisfaction and errors encountered. This feedback resulted in modifications to My Wellbeing Journal, which can be used during clinical encounters to facilitate communication, goal setting and progress tracking. DISCUSSION AND CONCLUSIONS: Clinicians and carers can use the tool to guide discussions with older adults about their care planning and help them set realistic goals that are meaningful to them. The findings of this study could be used to inform the development of recommendations for healthcare providers to implement person-centred, goal-oriented care for older adults with chronic conditions and multimorbidity. PATIENT OR PUBLIC CONTRIBUTION: Older adults living with chronic conditions and multimorbidity and their carers have contributed to the development of a tool that has the potential to significantly enhance the experience of personalised care planning. Their direct involvement as collaborators has ensured that the tool is optimised to meet the standards of effectiveness and usability.

Multiparametric Immunoimaging Maps Inflammatory Signatures in Murine Myocardial Infarction Models.

In the past 2 decades, research on atherosclerotic cardiovascular disease has uncovered inflammation to be a key driver of the pathophysiological process. A pressing need therefore exists to quantitatively and longitudinally probe inflammation, in preclinical models and in cardiovascular disease patients, ideally using non-invasive methods and at multiple levels. Here, we developed and employed in vivo multiparametric imaging approaches to investigate the immune response following myocardial infarction. The myocardial infarction models encompassed either transient or permanent left anterior descending coronary artery occlusion in C57BL/6 and Apoe-/-mice. We performed nanotracer-based fluorine magnetic resonance imaging and positron emission tomography (PET) imaging using a CD11b-specific nanobody and a C-C motif chemokine receptor 2-binding probe. We found that immune cell influx in the infarct was more pronounced in the permanent occlusion model. Further, using 18F-fluorothymidine and 18F-fluorodeoxyglucose PET, we detected increased hematopoietic activity after myocardial infarction, with no difference between the models. Finally, we observed persistent systemic inflammation and exacerbated atherosclerosis in Apoe-/- mice, regardless of which infarction model was used. Taken together, we showed the strengths and capabilities of multiparametric imaging in detecting inflammatory activity in cardiovascular disease, which augments the development of clinical readouts.