Signaling Dynamics in Osteogenesis: Unraveling Therapeutic Targets for Bone Generation.

Diseases affecting bone encompass a spectrum of disorders, from prevalent conditions such as osteoporosis and Paget's disease, collectively impacting millions, to rare genetic disorders including Fibrodysplasia Ossificans Progressiva (FOP). While several classes of drugs, such as bisphosphonates, synthetic hormones, and antibodies, are utilized in the treatment of bone diseases, their efficacy is often curtailed by issues of tolerability and high incidence of adverse effects. Developing therapeutic agents for bone diseases is hampered by the fact that numerous pathways regulating bone metabolism also perform pivotal functions in other organ systems.

Delphi-driven consensus definition for mesenchymal stromal cells and clinical reporting guidelines for mesenchymal stromal cell-based therapeutics.

Background Aims: Despite promising results in pre-clinical studies, mesenchymal stromal cells (MSCs) face significant challenges in clinical translation. A scoping review by our group highlighted two key issues contributing to this gap: (i) lack of a clear and consensus definition for MSCs and (ii) under-reporting of critical parameters in MSC clinical studies. To address these issues, we conducted a modified Delphi study to establish and implement a consensus definition for MSCs and develop reporting guidelines for MSC clinical studies.

Alexander Friedenstein, Mesenchymal Stem Cells, Shifting Paradigms and Euphemisms.

Six decades ago, Friedenstein and coworkers published a series of seminal papers identifying a cell population in bone marrow with osteogenic potential, now referred to as mesenchymal stem cells (MSCs). This work was also instrumental in establishing the identity of hematopoietic stem cell and the identification of skeletal stem/progenitor cell (SSPC) populations in various skeletal compartments. In recognition of the centenary year of Friedenstein's birth, I review key aspects of his work and discuss the evolving concept of the MSC and its various euphemisms indorsed by changing paradigms in the field.

Comparative transcriptome analysis of bone marrow resident versus culture-expanded mouse mesenchymal stem/stromal cells.

Background Aims: Mesenchymal stem/stromal cells (MSCs) are defined as culture-expanded populations, and although these cells recapitulate many properties of bone marrow (BM) resident skeletal stem/progenitor cells, few studies have directly compared these populations to evaluate how culture adaptation and expansion impact critical quality attributes.

Methods: We analyzed by RNA sequencing LinSCA1 MSCs enriched from BM by immunodepletion (ID) and after subsequent culture expansion (Ex) and LinLEPR MSCs sorted (S) directly from BM. Pairwise comparisons were used to identify differentially expressed genes (DEGs) between populations, and gene set enrichment analysis was employed to identify biological pathways/processes unique to each population.

Novel role for alpha-2-macroglobulin (A2M) as a disease modifying protein in senile osteoporosis.

In the rapidly aging U.S. population, age-induced bone loss (senile osteoporosis) represents a major public health concern that is associated with a significant increased risk for low trauma fragility fractures, which are debilitating to patients, cause significant morbidity and mortality, and are costly to treat and manage.

and are coordinately regulated and function as potency biomarkers in human MSCs.

Mesenchymal stem/stromal cells (MSCs) have been evaluated in >1500 clinical trials, but outcomes remain suboptimal because of knowledge gaps in quality attributes that confer potency. We show that TWIST1 directly represses expression that and are inversely correlated across bone marrow-derived MSC (BM-MSC) donor cohorts and predict interdonor differences in their proangiogenic, anti-inflammatory, and immune suppressive activity in vitro and in sterile inflammation and autoimmune type 1 diabetes preclinical models. Transcript profiling of versus BM-MSCs revealed previously unidentified roles for TWIST1/TSG6 in regulating cellular oxidative stress and TGF-β2 in modulating expression and anti-inflammatory activity.

Graph neural networks for the identification of novel inhibitors of a small RNA.

MicroRNAs (miRNAs) play a crucial role in post-transcriptional gene regulation and have been implicated in various diseases, including cancers and lung disease. In recent years, Graph Neural Networks (GNNs) have emerged as powerful tools for analyzing graph-structured data, making them well-suited for the analysis of molecular structures. In this work, we explore the application of GNNs in ligand-based drug screening for small molecules targeting miR-21.

Transcriptional Targets of TWIST1 in Human Mesenchymal Stem/Stromal Cells Mechanistically Link Stem/Progenitor and Paracrine Functions.

Despite extensive clinical testing, mesenchymal stem/stromal cell (MSC)-based therapies continue to underperform with respect to efficacy, which reflects the paucity of biomarkers that predict potency prior to patient administration. Previously, we reported that TWIST1 predicts inter-donor differences in MSC quality attributes that confer potency. To define the full spectrum of TWIST1 activity in MSCs, the present work employed integrated omics-based profiling to identify a high-confidence set of TWIST1 targets, which mapped to cellular processes related to ECM structure/organization, skeletal and circulatory system development, interferon gamma signaling, and inflammation.

Implementation Evaluation of a Teledermatology Virtual Clinic at an Academic Medical Center.

Background: Teledermatology (TD) is an evidence-based practice that may increase access to dermatologic care. We sought to evaluate implementation of TD at four Duke primary care practices.

Methods: We implemented a hybrid TD program where trained primary care providers (PCPs) sent referrals with clinical and dermatoscopic images to dermatology.

Revisiting the Mesenchymal "Stem vs. Stromal" Cell Dichotomy and Its Implications for Development of Improved Potency Metrics.

Mesenchymal stem/stromal cell (MSC)-based therapies have been evaluated in over 1500 human clinical trials for a diverse array of disease indication, but outcomes remain unpredictable due to knowledge gaps in the quality attributes that confer therapeutic potency onto cells and their mode of action in vivo. Based on accumulated evidence from pre-clinical models, MSCs exert therapeutic effects by repressing inflammatory and immune-mediated response via paracrine action following reprogramming by the host injury microenvironment, and by polarization of tissue resident macrophages following phagocytosis to an alternatively activated (M2) state. An important tenet of this existing paradigm is that well-established stem/progenitor functions of MSCs are independent of paracrine function and dispensable for their anti-inflammatory and immune suppressive functions.

Mesenchymal stem/stromal cells from a transplanted, asymptomatic patient with Fanconi anemia exhibit an aging-like phenotype and dysregulated expression of genes implicated in hematopoiesis and myelodysplasia.

Background Aims: Fanconi anemia (FA) is an inherited bone marrow failure syndrome caused by defects in the repair of DNA inter-strand crosslinks and manifests as aplastic anemia, myelodysplastic syndrome and acute myeloid leukemia. FA also causes defects in mesenchymal stromal cell (MSC) function, but how different FA gene mutations alter function remains understudied.

Methods: We compared the growth, differentiation and transcript profile of a single MSC isolate from an asymptomatic patient with FA with a FANCG nonsense mutation who underwent hematopoietic stem cell transplantation 10 years prior to that from a representative healthy donor (HD).

Pharmacological Inhibition of Inositol Hexakisphosphate Kinase 1 Protects Mice against Obesity-Induced Bone Loss.

Obesity and type II diabetes mellitus (T2DM) are prominent risk factors for secondary osteoporosis due to the negative impacts of hyperglycemia and excessive body fat on bone metabolism. While the armamentarium of anti-diabetic drugs is expanding, their negative or unknown impacts on bone metabolism limits effectiveness. The inactivation of inositol hexakisphosphate kinase 1 (IP6K1) protects mice from high-fat-diet (HFD)-induced obesity (DIO) and insulin resistance by enhancing thermogenic energy expenditure, but the role of this kinase and the consequences of its inhibition on bone metabolism are unknown.

Strategies for targeting RNA with small molecule drugs.

Introduction: Historically, therapeutic treatment of disease has been restricted to targeting proteins. Of the approximately 20,000 translated human proteins, approximately 1600 are associated with diseases. Strikingly, less than 15% of disease-associated proteins are predicted or known to be 'druggable.

eConsults' Impact on Care Access and Wait Times in Rheumatology.

Background/objective: A growing number of health systems have implemented eConsults to improve access to specialty advice, but few studies have described their use in rheumatology or impact on visit wait times. We evaluated the uptake of an eConsult program and its impact on wait times for in-person rheumatology visits.

Methods: In this quality improvement project, we analyzed electronic health record data from 4 intervention clinics and 4 comparison clinics, 12 months before and after implementation of an eConsult program.

Transcriptional responses of skeletal stem/progenitor cells to hindlimb unloading and recovery correlate with localized but not systemic multi-systems impacts.

Disuse osteoporosis (DO) results from mechanical unloading of weight-bearing bones and causes structural changes that compromise skeletal integrity, leading to increased fracture risk. Although bone loss in DO results from imbalances in osteoblast vs. osteoclast activity, its effects on skeletal stem/progenitor cells (SSCs) is indeterminate.

Implementing video visits into an orthopedic hip arthroscopy practice: a case study.

Telehealth videoconferencing has been shown to be feasible, cost-effective and safe in numerous fields of medicine. In an effort to increase access and improve the quality of care offered to patients we implemented a telehealth initiative allowing for remote orthopedic clinic visits at a major academic medical center. Here we report on our experience and early outcomes.

Mesenchymal Stem Cell (MSC)-Derived Extracellular Vesicles Protect from Neonatal Stroke by Interacting with Microglial Cells.

Mesenchymal stem cell (MSC)-based therapies are beneficial in models of perinatal stroke and hypoxia-ischemia. Mounting evidence suggests that in adult injury models, including stroke, MSC-derived small extracellular vesicles (MSC-sEV) contribute to the neuroprotective and regenerative effects of MSCs. Herein, we examined if MSC-sEV protect neonatal brain from stroke and if this effect is mediated via communication with microglia.

Consensus International Council for Commonality in Blood Banking Automation-International Society for Cell & Gene Therapy statement on standard nomenclature abbreviations for the tissue of origin of mesenchymal stromal cells.

The Cellular Therapy Coding and Labeling Advisory Group of the International Council for Commonality in Blood Banking Automation and the International Society for Cell & Gene Therapy mesenchymal stromal cell (MSC) committee are providing specific recommendations on abbreviating tissue sources of culture-adapted MSCs. These recommendations include using abbreviations based on the ISBT 128 terminology model that specifies standard class names to distinguish cell types and tissue sources for culture-adapted MSCs. Thus, MSCs from bone marrow are MSC(M), MSCs from cord blood are MSC(CB), MSCs from adipose tissue are MSC(AT) and MSCs from Wharton's jelly are MSC(WJ).

Mesenchymal stem cell-derived extracellular vesicles reduce senescence and extend health span in mouse models of aging.

Aging drives progressive loss of the ability of tissues to recover from stress, partly through loss of somatic stem cell function and increased senescent burden. We demonstrate that bone marrow-derived mesenchymal stem cells (BM-MSCs) rapidly senescence and become dysfunctional in culture. Injection of BM-MSCs from young mice prolonged life span and health span, and conditioned media (CM) from young BM-MSCs rescued the function of aged stem cells and senescent fibroblasts.