Faculty Bibliography

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.

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.

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.

Peritoneal cavity fluid and mesothelial surfaces host distinct resident macrophage populations, among which include the well-described Gata6⁺ large cavity macrophages (LCMs) in peritoneal fluid. Here, we reveal that LCMs arise from two separable differentiation pathways. In the quantitatively minor pathway, monocytes gave rise to LYVE1⁺ LCMs but few Gata6⁺ LCMs. This pathway did not require the transcription factor Gata6 but was severely impaired in mice bearing three mutations in the -165 kb Zeb2 enhancer (Zeb2

Primordial germ cells (PGCs) are the first cells specified in the Drosophila embryo and are precursors to the germline. Their formation requires suppression of somatic fates, achieved by degrading the receptor tyrosine kinase Torso at the posterior pole through the ubiquitin ligase adaptor germ cell-less (GCL). Although Torso is known to antagonize PGC formation, the underlying mechanisms remained unclear. Here, we combine optogenetic Ras activation and Ras effector loop mutants to show that Ras suppresses PGC formation independently of the canonical Raf/MEK/ERK pathway. We identify an unexpected early role for Torso in activating phosphoinositide 3-kinase (PI3K), generating membrane domains enriched in phosphatidylinositol (3,4,5)-trisphosphate (PIP3). Elevated PI3K activity disrupts PGC formation, while reduced PI3K activity creates ectopic PGCs. We demonstrate that GCL remodels the posterior pole membrane by suppressing Torso-dependent PI3K activation. Clearing PIP3 enables myosin II enrichment, allowing for PGC formation. Together, our findings reveal how antagonistic Torso and GCL activities establish the soma-germline boundary by organizing cortical lipids.

The integrated stress response (ISR) coordinates cellular adaptation to diverse stress conditions. In Drosophila, two bZIP transcription factors, Xrp1 and crc (ATF4 homolog), are induced during ISR. Crc protein can dimerize with two CEBP factors in vitro, but the in vivo relevance of those interactions remained unknown. Here, we report that the CEBPG homolog, Irbp18, is an essential partner of crc during ISR. Specifically, Irbp18 is broadly required for the transcriptional induction of ISR target genes in the photoreceptors of ninaE^G69D, a Drosophila model of retinitis pigmentosa. Moreover, CUT&RUN analysis indicates that Irbp18 loss reduces or abolishes crc binding to target DNAs in photoreceptors and impairs crc's ability to induce target transcripts upon overexpression. Functionally, Irbp18 loss causes retinal degeneration and suppresses ISR signaling in parkin mutants, a model of Parkinson's disease. Together, these findings identify Irbp18 as a cofactor for crc, impacting pathological outcomes in Drosophila models of degeneration.

Mutations in the gene encoding the microtubule-associated protein tau (MAPT) that are causal for frontotemporal dementia result in nuclear envelope deformation and disrupted nucleocytoplasmic transport when expressed in human neurons. A small-molecule inhibitor of the acetyltransferase NAT10 has been shown to correct similar nuclear membrane defects in Hutchinson-Gilford progeria syndrome, primarily by modulating microtubule dynamics. We report here that NAT10 inhibition and loss of function correct nuclear membrane abnormalities in human MAPT-mutant neurons. Similarly, NAT10 inhibition and haploinsufficiency correct neuronal nuclear shape defects and extend lifespan in vivo in a Drosophila model of tauopathy. NAT10 inhibition changes microtubule dynamics and corrects aberrant nucleocytoplasmic transport, and NAT10 directly interacts with regulators of microtubule dynamics in human MAPT-mutant neurons. We conclude that NAT10 mediates neuronal pathologies in tauopathies and is a potential therapeutic target in these diseases.