Health outcomes are strongly impacted by social determinants of health, including social risk factors and patient demographics, due to structural inequities and discrimination. Primary care is viewed ...as a potential medical setting to assess and address individual health-related social needs and to collect detailed patient demographics to assess and advance health equity, but limited literature evaluates such processes.
We conducted an analysis of cross-sectional survey data collected from n = 507 Maryland Primary Care Program (MDPCP) practices through Care Transformation Requirements (CTR) reporting in 2022. Descriptive statistics were used to summarize practice responses on social needs screening and demographic data collection. A stepwise regression analysis was conducted to determine factors predicting screening of all vs. a targeted subset of beneficiaries for unmet social needs.
Almost all practices (99%) reported conducting some form of social needs screening and demographic data collection. Practices reported variation in what screening tools or demographic questions were employed, frequency of screening, and how information was used. More than 75% of practices reported prioritizing transportation, food insecurity, housing instability, financial resource strain, and social isolation.
Within the MDPCP program there was widespread implementation of social needs screenings and demographic data collection. However, there was room for additional supports in addressing some challenging social needs and increasing detailed demographics. Further research is needed to understand any adjustments to clinical care in response to identified social needs or application of data for uses such as assessing progress towards health equity and the subsequent impact on clinical care and health outcomes.
Constraint-based optimization, such as flux balance analysis (FBA), has become a standard systems-biology computational method to study cellular metabolisms that are assumed to be in a steady state ...of optimal growth. The methods are based on optimization while assuming (i) equilibrium of a linear system of ordinary differential equations, and (ii) deterministic data. However, the steady-state assumption is biologically imperfect, and several key stoichiometric coefficients are experimentally inferred from situations of inherent variation. We propose an approach that explicitly acknowledges heterogeneity and conducts a robust analysis of metabolic pathways (RAMP). The basic assumption of steady state is relaxed, and we model the innate heterogeneity of cells probabilistically. Our mathematical study of the stochastic problem shows that FBA is a limiting case of our RAMP method. Moreover, RAMP has the properties that: A) metabolic states are (Lipschitz) continuous with regards to the probabilistic modeling parameters, B) convergent metabolic states are solutions to the deterministic FBA paradigm as the stochastic elements dissipate, and C) RAMP can identify biologically tolerable diversity of a metabolic network in an optimized culture. We benchmark RAMP against traditional FBA on genome-scale metabolic reconstructed models of E. coli, calculating essential genes and comparing with experimental flux data.
The mitochondrial enzyme dihydroorotate dehydrogenase (DHODH) catalyzes one of the rate‐limiting steps in de novo pyrimidine biosynthesis, a pathway that provides essential metabolic precursors for ...nucleic acids, glycoproteins, and phospholipids. DHODH inhibitors (DHODHi) are clinically used for autoimmune diseases and are emerging as a novel class of anticancer agents, especially in acute myeloid leukemia (AML) where pyrimidine starvation was recently shown to reverse the characteristic differentiation block in AML cells. Herein, we show that DHODH blockade rapidly shuts down protein translation in leukemic stem cells (LSCs) and has potent and selective activity against multiple AML subtypes. Moreover, we find that ablation of CDK5, a gene that is recurrently deleted in AML and related disorders, increases the sensitivity of AML cells to DHODHi. Our studies provide important molecular insights and identify a potential biomarker for an emerging strategy to target AML.
Synopsis
This study reports that AG636, an inhibitor of the metabolic enzyme DHODH, has excellent potency against acute myeloid leukemia (AML) in pre‐clinical models.
AG636 exhibits potent activity against different AML subtypes in vivo, promoting a combination of cell death and differentiation and effectively reducing leukemic stem cells.
DHODH inhibition has a moderate impact on normal blood development, but the effects are temporary with hematopoietic populations recovering after treatment cessation.
Pyrimidine starvation limits nascent protein synthesis, in part through downregulating YY1.
Loss of CDK5, a gene recurrently deleted in a subset of patients with aggressive disease, alters the molecular response of leukemic cells to AG636 and increases their sensitivity to drug treatment.
This study reports that AG636, an inhibitor of the metabolic enzyme DHODH, has excellent potency against acute myeloid leukemia (AML) in pre‐clinical models.
Estrogen receptor-positive breast cancers (ER
BCas) are the most common form of BCa and are increasing in incidence, largely due to changes in reproductive practices in recent decades. Tamoxifen is ...prescribed as a component of standard-of-care endocrine therapy for the treatment and prevention of ER
BCa. However, it is poorly tolerated, leading to low uptake of the drug in the preventative setting. Alternative therapies and preventatives for ER
BCa are needed but development is hampered due to a paucity of syngeneic ER
preclinical mouse models that allow pre-clinical experimentation in immunocompetent mice. Two ER-positive models, J110 and SSM3, have been reported in addition to other tumour models occasionally shown to express ER (for example 4T1.2, 67NR, EO771, D2.0R and D2A1). Here, we have assessed ER expression and protein levels in seven mouse mammary tumour cell lines and their corresponding tumours, in addition to their cellular composition, tamoxifen sensitivity and molecular phenotype. By immunohistochemical assessment, SSM3 and, to a lesser extent, 67NR cells are ER
. Using flow cytometry and transcript expression we show that SSM3 cells are luminal in nature, whilst D2.0R and J110 cells are stromal/basal. The remainder are also stromal/basal in nature; displaying a stromal or basal Epcam/CD49f FACS phenotype and stromal and basal gene expression signatures are overrepresented in their transcript profile. Consistent with a luminal identity for SSM3 cells, they also show sensitivity to tamoxifen in vitro and in vivo. In conclusion, the data indicate that the SSM3 syngeneic cell line is the only definitively ER
mouse mammary tumour cell line widely available for pre-clinical research.
Background Social needs screening can help modify care delivery to meet patient needs and address non-medical barriers to optimal health. However, there is a need to understand how factors that exist ...at multiple levels of the healthcare ecosystem influence the collection of these data in primary care settings. Methods We conducted 20 semi-structured interviews involving healthcare providers and primary care clinic staff who represented 16 primary care practices. Interviews focused on barriers and facilitators to awareness of and assistance for patients' social needs in primary care settings in Maryland. The interviews were coded to abstract themes highlighting barriers and facilitators to conducting social needs screening. The themes were organized through an inductive approach using the socio-ecological model delineating individual-, clinic-, and system-level barriers and facilitators to identifying and addressing patients' social needs. Results We identified several individual barriers to awareness, including patient stigma about verbalizing social needs, provider frustration at eliciting needs they were unable to address, and provider unfamiliarity with community-based resources to address social needs. Clinic-level barriers to awareness included limited appointment times and connecting patients to appropriate community-based organizations. System-level barriers to awareness included navigating documentation challenges on the electronic health record. Conclusions Overcoming barriers to effective screening for social needs in primary care requires not only practice- and provider-level process change but also an alignment of community resources and advocacy of policies to redistribute community assets to address social needs.
Biologic drugs are typically manufactured in mammalian host cells, and it is critical from a drug safety and efficacy perspective to detect and remove host cell proteins (HCPs) during production. ...This is currently achieved with sets of polyclonal antibodies (pAbs), but these suffer from critical shortcomings because their composition is inherently undefined, and they cannot detect nonimmunogenic HCPs. In this work, we report a high-throughput screening and array-based binding characterization strategy that we employed to generate a set of aptamers that overcomes these limitations to achieve sensitive, broad-spectrum detection of HCPs from the widely used Chinese hamster ovary (CHO) cell line. We identified a set of 32 DNA aptamers that achieve better sensitivity than a commercial pAb reagent set and can detect a comparable number of HCPs over a broad range of isoelectric points and sizes. Importantly, these aptamers detect multiple contaminants that are known to be responsible for therapeutic antibody degradation and toxicity in patients. Because HCP aptamer reagents are sequence-defined and chemically synthesized, we believe they may enable safer production of biologic drugs, and this strategy should be broadly applicable for the generation of HCP detection reagents for other cell lines.
The dendritic cell receptor Clec9A facilitates processing of dead cell-derived antigens for cross-presentation and the induction of effective CD8
T cell immune responses. Here, we show that this ...process is regulated by E3 ubiquitin ligase RNF41 and define a new ubiquitin-mediated mechanism for regulation of Clec9A, reflecting the unique properties of Clec9A as a receptor specialized for delivery of antigens for cross-presentation. We reveal RNF41 is a negative regulator of Clec9A and the cross-presentation of dead cell-derived antigens by mouse dendritic cells. Intriguingly, RNF41 regulates the downstream fate of Clec9A by directly binding and ubiquitinating the extracellular domains of Clec9A. At steady-state, RNF41 ubiquitination of Clec9A facilitates interactions with ER-associated proteins and degradation machinery to control Clec9A levels. However, Clec9A interactions are altered following dead cell uptake to favor antigen presentation. These findings provide important insights into antigen cross-presentation and have implications for development of approaches to modulate immune responses.
Identification of metabolic pathways that are dysregulated in acute myeloid leukaemia (AML) offers significant promise for the development of new therapeutic strategies. Heme is an essential ...metabolite with broad biological activity that is required and produced by all cells. In addition to its catalytic role as a cofactor in hemoproteins, heme also directly regulates signalling and gene expression. We and others have shown that heme biosynthesis enzymes are among the most downregulated genes during AML progression; and large-scale CRISPR screening studies have revealed that AML cells have an increased dependence on the expression of pathway components. We analysed heme biosynthesis in mouse models, AML cell lines and patient samples and found that common AML driver genes cause reduced heme production capacity in leukaemic cells. The low heme state in turn affects mitochondrial metabolism and drives altered gene expression patterns, in part via heme sensing transcription factors including BACH1. In proof-of concept experiments we demonstrate that low heme AML cells have increased sensitivity to inhibitors of the electron transport chain and drugs that induce ferroptosis. Using unbiased CRISPR screening methodologies we are now uncovering novel biochemical pathways that are synthetic lethal with heme metabolism. Altogether, our data points to a model where low heme biosynthesis promotes metabolic and transcriptional programs that are beneficial for self-renewal but also result in vulnerabilities that can be exploited for therapeutic benefit.
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