Six time points after myotoxin injury, we collected an integrated atlas of single-cell transcriptomes, comprising 273,923 profiles, from the muscles of young, old, and geriatric mice (5, 20, and 26 months old). Eight cell types, including subsets of T cells, NK cells, and macrophages, showed differing response kinetics across age groups, with some showing accelerated and others slower dynamics. Pseudotime analysis allowed us to delineate myogenic cell states and trajectories that are specifically related to old and geriatric age groups. To evaluate cellular senescence, which explains age-related differences, we employed experimentally derived and curated gene lists. The observation highlighted a rise in senescent-like cell populations, particularly within the self-renewing muscle stem cells of aged musculature. A holistic view of altered cellular states in skeletal muscle regeneration, as seen across a mouse's lifespan, is provided by this resource.
Myogenic and non-myogenic cells, working in concert with precise spatial and temporal coordination, are critical for skeletal muscle regeneration. The decline in skeletal muscle's regenerative capacity with advancing age arises from modifications in the characteristics and activities of myogenic stem/progenitor cells, along with contributions from non-myogenic cells, and from systemic changes, all of which worsen over time. micromorphic media Understanding the intricate network of cell-intrinsic and cell-extrinsic modifications impacting muscle stem/progenitor cell contributions to muscle regeneration throughout the lifespan remains a significant challenge. A complete atlas documenting regenerative muscle cell states across a mouse's life cycle was created using 273,923 single-cell transcriptomes from hindlimb muscles of young, old, and geriatric (4-7, 20, and 26 months-old, respectively) mice at six time-points following myotoxin-induced injury. Our analysis revealed 29 distinct muscle cell types, with eight demonstrating altered abundance patterns across age groups. These included T cells, NK cells, and various macrophage subtypes, indicating that the aging-related decrease in muscle repair likely stems from a temporal imbalance in the inflammatory response. Dabrafenib The regeneration period of myogenic cells was analyzed using pseudotime, revealing age-specific trajectories of myogenic stem/progenitor cells in old and geriatric muscle. Cellular senescence, playing a critical role in restricting cellular activity in aged tissues, prompted the development of a set of bioinformatics tools for senescence identification in single-cell data, further assessing their performance in identifying senescence across key myogenic phases. Through a comparative analysis of single-cell senescence scores and the co-expression of hallmark senescence genes, we find
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The experimentally derived gene list from the muscle foreign body response (FBR) fibrosis model successfully identified senescent-like myogenic cells (receiver-operator curve AUC = 0.82-0.86) across diverse mouse ages, injury time points, and cell cycle states, exhibiting a performance comparable to existing curated lists. The scoring approach, correspondingly, characterized transient senescence subsets within the myogenic stem/progenitor cell trajectory, exhibiting a connection to impeded MuSC self-renewal across the entire age range of mice. This new resource, analyzing the aging of mouse skeletal muscle, details a comprehensive portrayal of the changing cellular states and interaction networks that underlie skeletal muscle regeneration throughout the mouse's lifespan.
Spatial and temporal coordination is critical to the regeneration of skeletal muscle, dependent on the interplay of myogenic and non-myogenic cells. The decline in skeletal muscle regenerative capacity associated with aging results from concurrent changes in myogenic stem/progenitor cell behavior, the contributions of non-myogenic cells, and comprehensive systemic alterations that accrue throughout the aging process. The complete network picture of cell-intrinsic and -extrinsic adjustments governing muscle stem/progenitor cell roles in muscle regeneration over a lifetime is not fully elucidated. We created a comprehensive atlas of regenerative muscle cell states throughout a mouse's life by collecting 273,923 single-cell transcriptomes from hindlimb muscles of mice at different ages (young, old, and geriatric, 4-7, 20, and 26 months, respectively) and at six closely spaced intervals after myotoxin injury. Our research uncovered 29 muscle-resident cell types; eight demonstrated shifts in abundance across age groups, such as T cells, NK cells, and various macrophage subtypes. This suggests a possible link between age-related muscle repair decline and a temporal misalignment in the inflammatory response. We analyzed myogenic cell pseudotime across regeneration periods and observed age-specific trajectories of myogenic stem/progenitor cells in old and geriatric muscle tissues. Due to the significant part played by cellular senescence in restricting cellular activities in aged tissues, we constructed a set of bioinformatics tools. These tools are aimed at identifying senescence in single-cell data, and evaluating their ability to ascertain senescence during significant myogenic developmental stages. In our study, we correlated single-cell senescence scores with the co-expression of hallmark senescence genes Cdkn2a and Cdkn1a, revealing that a gene list derived from an experimental muscle foreign body response (FBR) fibrosis model accurately (receiver-operator curve AUC = 0.82-0.86) identified senescent-like myogenic cells regardless of mouse age, injury timing, or cell cycle position, displaying performance comparable to curated gene lists. In addition, this scoring strategy delineated transitory senescence subgroups within the myogenic stem/progenitor cell line, correlating with the stalled MuSC self-renewal states in mice of every age. This new resource examines mouse skeletal muscle aging, illuminating the transformative cellular states and intricate network interactions driving skeletal muscle regeneration throughout the mouse's life cycle.
Of the pediatric patients undergoing cerebellar tumor resection, roughly 25% are observed to develop cerebellar mutism syndrome. We have recently observed a link between injury to the cerebellar deep nuclei and superior cerebellar peduncles, which we refer to as the cerebellar outflow pathway, and an increased likelihood of developing CMS. We assessed the replicability of these results within an independent patient cohort. A study of 56 pediatric patients following cerebellar tumor resection investigated whether the location of the lesion correlated with the development of CMS. We predicted that CMS+ individuals, relative to those without CMS (CMS-), would demonstrate lesions preferentially intersecting with 1) the cerebellar outflow route and 2) a pre-existing lesion-symptom map for CMS. In keeping with pre-registered hypotheses and analytic procedures, analyses were executed (https://osf.io/r8yjv/). Femoral intima-media thickness The evidence we obtained provided strong support for each of the hypotheses. CMS+ patients (n=10) demonstrated lesions exhibiting a higher degree of overlap with the cerebellar outflow pathway than CMS- patients (Cohen's d = .73, p = .05), and also displayed greater overlap on the CMS lesion-symptom map (Cohen's d = 11, p = .004). These findings reinforce the connection between lesion site and the likelihood of CMS development, demonstrating consistent results across different groups of participants. The implications of these results for the most suitable surgical procedures in treating pediatric cerebellar tumors could be significant.
Health system interventions aimed at enhancing hypertension and CVD care have received comparatively few rigorous evaluations in sub-Saharan Africa. The Ghana Heart Initiative (GHI), a multifaceted supply-side intervention to promote cardiovascular health in Ghana, will be assessed for its accessibility, effectiveness, receptiveness, implementation accuracy, cost analysis, and long-term efficacy. A mixed-methods, multi-method analysis is conducted in this study to compare the impact of the GHI on the performance of the 42 intervention health facilities. Evaluating the differences between primary, secondary, and tertiary healthcare facilities in the Greater Accra Region and a control group of 56 facilities in the Central and Western Regions. Evaluation design is driven by the RE-AIM framework, with the WHO health systems building blocks as its foundation, further incorporating the Institute of Medicine's six dimensions of healthcare quality: safe, effective, patient-centered, timely, efficient, and equitable. Assessment tools incorporate a health facility survey, a healthcare provider survey evaluating their knowledge, attitudes, and practices on hypertension and cardiovascular disease management, a patient exit survey, a comprehensive review of outpatient and inpatient medical records, and qualitative interviews with patients and key health system stakeholders to uncover the barriers and facilitators of the Global Health Initiative's deployment. Besides collecting primary data, the study also utilizes the District Health Information Management System's routine secondary data. This is used to execute an interrupted time series analysis, using monthly counts of hypertension and CVD-specific indicators as outcomes. Key performance indicators for health service delivery, encompassing input, process, and outcome measures (like hypertension screening, new hypertension diagnoses, adherence to guideline-directed medical therapies, and patient satisfaction with and acceptance of services), will be assessed between intervention and control facilities to determine primary outcomes. At last, a forthcoming economic evaluation, coupled with a budget impact analysis, is designed to inform the nation-wide implementation of the GHI. The GHI's reach, effectiveness, implementation precision, acceptability, and durability will be explored in this study, which will yield policy-relevant data. Insights on associated costs and budgetary effects will inform nationwide scaling, extending the GHI across Ghana, while providing lessons for other low- and middle-income countries.