Faculty Bibliography

The divalent anion sodium symporter (DASS) family mediates the uptake of Krebs cycle intermediates and sulfate and influences adiposity, insulin resistance, and metabolism in mammals. While Na⁺:substrate stoichiometry is known for several DASS transporters, the location of key Na⁺-binding sites remains elusive; important information for understanding the mechanism. In VcINDY, a bacterial DASS protein, we visualized a nonprotein cryo-electron microscopy (cryo-EM) density in the middle of the transport domain. Its size and coordination suggest that it may represent either a third Na⁺ ion or a structural water molecule. Using a combination of in vitro binding and transport assays, cryo-EM structural determination, and molecular dynamic simulations, we show that the density is not a Na⁺ ion. Instead, the data indicate that the density likely represents a structural water molecule critical for transport domain integrity. Sequence and structural similarities suggest this feature may be conserved across human DASS transporters such as NaCT and NaDC3.

The divalent anion sodium symporter (DASS) family mediates the uptake of Krebs cycle intermediates and sulfate and influences adiposity, insulin resistance, and metabolism in mammals. While Na⁺:substrate stoichiometry is known for several DASS transporters, the location of key Na⁺-binding sites remains elusive; important information for understanding the mechanism. In VcINDY, a bacterial DASS protein, we visualized a nonprotein cryo-electron microscopy (cryo-EM) density in the middle of the transport domain. Its size and coordination suggest that it may represent either a third Na⁺ ion or a structural water molecule. Using a combination of in vitro binding and transport assays, cryo-EM structural determination, and molecular dynamic simulations, we show that the density is not a Na⁺ ion. Instead, the data indicate that the density likely represents a structural water molecule critical for transport domain integrity. Sequence and structural similarities suggest this feature may be conserved across human DASS transporters such as NaCT and NaDC3.

BACKGROUND/UNASSIGNED:Obesity is associated with a loss of anti-inflammatory regulatory T cells (Tregs) in adipose tissue (AT), resulting in systemic inflammation. The adipocyte is a central modulator of CD4+T-cell subpopulations via antigen presentation through the MHCII (major histocompatibility complex class II). However, the role of adipocyte-induced AT inflammation due to changes in AT Tregs in obesity-related complications, such as atherosclerosis and metabolic-dysfunction-associated fatty liver disease (MAFLD), remains unknown. METHODS/UNASSIGNED:mice fed a Western high-fat diet for 12 weeks. We used 1-year-old mice because, unlike young mice, they develop markedly accelerated atherosclerosis like humans. RESULTS/UNASSIGNED:) ingesting a Western high-fat diet, had no effect on disease progression. CONCLUSIONS/UNASSIGNED:These results suggest that AT immunosuppressive T cells play a pivotal role in regulating both atherosclerosis development and liver fat accumulation in obesity.

Alopecia areata (AA) is an autoimmune hair disease with variable presentations necessitating individualized, stepwise management given patient age, extent of involvement, comorbidities, and treatment tolerability. Historically, severity was defined by percentage of scalp hair loss using the Severity of Alopecia Tool (SALT), with SALT≥50 defining severe disease and systemic therapy eligibility. Recently, severity assessment has expanded beyond scalp involvement with the AA Scale for Clinical Use (AASc), incorporating eyebrow/eyelash involvement, psychosocial impairment, and treatment response to better capture disease burden. First-line therapy for mild-to-moderate AA (SALT<50) includes topical or intralesional corticosteroids, often with topical or oral minoxidil. Observation may be appropriate in select cases given potential for spontaneous regrowth. FDA approval of oral Janus kinase inhibitors (JAKis) for severe AA (SALT≥50) has changed the therapeutic landscape. Selection among baricitinib, ritlecitinib, and deuruxolitinib is guided by patient age, safety considerations, comorbidities, laboratory monitoring, and insurance coverage. Switching between JAKis may still be beneficial after nonresponse to one agent. Adjunctive and alternative therapies include topical immunotherapy, systemic immunosuppressants, emerging biologic/targeted therapies, and procedural modalities, such as platelet-rich plasma, laser- and light-based therapies, and microneedling. This review synthesizes current evidence on AA treatment and offers a practical, contemporary framework for AA management.

BACKGROUND:Penetrating trauma disproportionately affects young patients, yet many survivors cannot be discharged directly home and instead require post-acute care. Identifying these patients early could expedite rehabilitation referral and discharge planning, but no validated tool predicts non-home discharge in penetrating trauma. We developed and internally validated the Penetrating Injury Risk of Non-home Discharge (PIRD) score. METHODS:Using the National Trauma Data Bank (NTDB) Trauma Quality Improvement Program Participant Use Files (2019-2024), we selected adult patients (≥18 years) with penetrating trauma who survived to discharge. The outcome was non-home discharge to post-acute care (e.g., skilled nursing or inpatient rehabilitation) versus home. The cohort was split 2:1 into derivation and validation sets, stratified by outcome. Candidate predictors available early in the hospital course (demographics, insurance, mechanism, emergency-department physiology, the Injury Severity Score [ISS], body-region injury, transport, and comorbidities) underwent univariate screening, collinearity assessment, and backward-stepwise multivariable logistic regression. Unlike the orthopedic FORD score, ISS was retained because penetrating trauma is a high-severity, mortality-driven population. Coefficients were converted to integer points, scaled 0-10. RESULTS:Among 302,399 patients, 21,186 (7.0%) had non-home discharge. The 40-predictor model was led by spinal-cord injury, critical injury severity (ISS ≥25), advanced age, and severe traumatic brain injury, whereas stab mechanism and private-vehicle arrival lowered the odds. Validation discrimination was strong (area under the receiver operating characteristic curve [AUROC] 0.866, 95% confidence interval 0.861-0.871) with excellent calibration (Brier 0.046, calibration slope 1.00), exceeding the GTOS-II, TRIAGES, FORD, and DEPARTS scores (all p < 0.001). Non-home discharge rose from 0.7% (low risk) to 37.5% (high risk); at a score ≥4, sensitivity was 86.0% and negative predictive value 98.5%. CONCLUSION/CONCLUSIONS:Derived from variables available early in care, the PIRD score accurately predicts post-acute care discharge in adult penetrating trauma and outperforms existing severity scores, supporting timely discharge planning and resource allocation.

The organization of diverse mesenchymal populations during human small intestinal development is critical for tissue architecture and function yet remains poorly defined. Here, to construct a comprehensive, tissue-scale map of the developing human small intestine at single cell resolution, we leveraged single-cell RNA-sequencing data to build a Xenium spatial transcriptomics gene panel covering the cell diversity of the human small intestine. We defined five subpopulations occupying discrete anatomical locations within the lamina propria and submucosa-the subepithelial cells, lamina propria fibroblasts, submucosal fibroblasts, smooth muscle cells and CXCL13⁺ fibroblasts. Our data establish molecular markers to distinguish these populations in both sequencing and imaging data. We leverage this high-resolution atlas to interrogate cell-cell signalling, benchmark pluripotent stem cell-derived human intestinal organoids and to demonstrate how this resource can incorporate relative spatial organization into tissue analysis, with broad implications for modelling development, regeneration and disease.

Cryo-electron tomography (cryo-ET) has emerged as a transformative technique for visualizing the native ultrastructure of eukaryotic parasites, from proteins to cellular architecture. Recent technical advances in sample preparation, data collection, and computational analysis have enabled unprecedented insights into structural cell biology of medically important pathogens including Toxoplasma gondii, Plasmodium falciparum, Trypanosoma brucei and Trypanosoma cruzi, Cryptosporidium parvum, and Microsporidia. This review highlights the range of resolutions and cellular structures accessible by cryo-ET, and the kinds of biological insights that may be obtained, using eukaryotic parasites as case studies. Lower-resolution data (20-30 Å) provide structural information on organelles, whole-cells, and cell-cell interactions, while at the higher-resolution end, near-atomic structures can be resolved in situ using subtomogram averaging, typically for large, abundant particles such as ribosomes. Combined with orthogonal techniques, cryo-ET is a powerful tool for studying the structural cell biology of parasites.

PURPOSE OF REVIEW/OBJECTIVE:Despite aggressive cholesterol lowering, many patients continue to experience cardiovascular events ("residual risk"), emphasizing the need for novel risk reduction strategies. This review highlights recent advances in studying atherosclerosis resolution, with a focus on the key role played by plaque inflammation. RECENT FINDINGS/RESULTS:Preclinical studies demonstrate that while atherosclerosis resolution can involve plaque size reductions, more important are changes in plaque remodeling, as measured by necrotic core, CD68 area, and collagen content. Resolution can be partially achieved with cholesterol lowering, inflammation resolution alone, or better yet, combination approaches. This review evaluates lipid-lowering strategies, as well as inflammation-targeting pathways involving efferocytosis, pro-resolving macrophages, platelets, and caloric restriction. Translational studies and clinical trials targeting inflammatory pathways, including interleukin (IL)-1β, IL-6, NLRP3, and pro-resolving mediators further support inflammation modulation as a therapeutic strategy. SUMMARY/CONCLUSIONS:Many preclinical models of atherosclerosis resolution promote significant plaque remodeling by lipid-lowering, inflammation resolution, or combination approaches. Many recent and currently recruiting clinical trials are testing the benefits of inflammation resolution to further reduce cardiovascular risk in at-risk patients.

Synucleinopathies are a group of neurodegenerative disorders characterized by the accumulation of aggregated α-synuclein (α-syn), including Parkinson's disease, Dementia with Lewy Bodies, and Multiple System Atrophy. These diseases are marked by locomotor and non-motor impairments, as well as mitochondrial dysfunction and the loss of dopaminergic (DA) neurons. We have developed several anti-α-syn single-domain antibodies (sdAbs) and demonstrated the diagnostic imaging potential of two of them and the acute therapeutic benefit of one in clearing α-syn in a mouse model. However, whether these sdAbs can suppress α-syn-mediated neuronal loss and locomotor impairment in vivo remains unclear. We evaluated the therapeutic potential of five anti-α-syn sdAbs to clear pathological α-syn in mouse neuronal culture and then demonstrated their in vivo efficacy in a Drosophila model of synucleinopathy. The sdAbs differed in their efficacy to lower levels of phospho-serine 129 α-syn, prevent loss of DA neurons, alleviate mitochondrial dysfunction, improve motor function, and prolong survival in synucleinopathy flies. The most effective sdAb, 2H1, has not been reported before. It binds strongly to the aggregation prone region of α-syn and robustly improves all these disease parameters. Additionally, that sdAb is associated with α-syn in the fly neurons, as shown through proximity dependent turboID biotinylation assays. The sdAb-turboID also biotinylated α-syn-associated proteins involved in synapse/vesicle trafficking pathways, pinpointing the location of their intracellular interaction. Our findings provide an insight into the therapeutic mechanism of action of these sdAbs and strongly support their clinical development.