Why Did New York State Hospitals Rank So Poorly?

BACKGROUND: According to the Centers for Medicare and Medicaid Services star ratings, New York State (NYS) hospitals are relatively poor performers, with 33% achieving 1 star compared with 5% of hospitals across the United States. OBJECTIVES: We compared NYS hospitals to all United States hospitals using Centers for Medicare and Medicaid Services Hospital Value-Based Purchasing (HVBP) and star ratings component measures. We perform risk adjustment for hospital and market characteristics associated poor performance. RESEARCH DESIGN: This was a cross-sectional observational study. SUBJECTS: All acute care hospitals in the United States which had HVBP scores for 2019 in April 21, 2021, Hospital Care Compare database. MEASURES: Analysis of variance was used to compare NYS hospitals to all United States hospitals. Multivariable-based risk adjustment was applied to NYS hospitals with adjustment for hospital characteristics (eg, occupancy, size), hospital fiscal ratios (eg, operating margin), and market characteristics (eg, percent of hospital market that has a high school diploma). RESULTS: NYS hospitals averaged lower patient satisfaction and higher readmissions. These domains were statistically significantly associated with lower socioeconomic status in the hospital market area. Risk adjustment reduced but did not eliminate these differences. NYS also performed poorly on pressure ulcers and deep vein thrombosis/pulmonary embolism prevention. NYS hospitals were similar to the United States in mortality and hospital-acquired infections. CONCLUSIONS: Differences in the demographic makeup of hospital markets account for some of the poor performance of NYS hospitals. Some aspects, such as long length of stay, may be associated with wider regional trends.

The geography of Medicare's hospital value-based purchasing in relation to market demographics.

OBJECTIVE: To illustrate the association between the sociodemographic characteristics of hospital markets and the geographic patterns of Medicare hospital value-based purchasing (HVBP) scores. DATA SOURCES AND STUDY SETTING: This is a secondary analysis of United States hospitals with a HVBP Total Performance Score (TPS) for 2019 in the Centers for Medicare and Medicaid Services (CMS) Hospital Compare database (4/2021 release) and American Community Survey (ACS) data for 2015-2019. STUDY DESIGN: This is a cross-sectional study using spatial multivariable autoregressive models with HVBP TPS and component domain scores as dependent variables and hospital market demographics as the independent variables. DATA COLLECTION/EXTRACTION METHODS: We calculated hospital market demographics using ZIP code level data from the ACS, weighted the 2019 CMS inpatient Hospital Service Area file. PRINCIPAL FINDINGS: Spatial autoregressive models using eight nearest neighbors with diversity index, race and ethnicity distribution, families in poverty, unemployment, and lack of health insurance among residents ages 19-64 years provided the best model fit. Diversity index had the highest statistically significant contribution to lower TPS (ß = -12.79, p < 0.0001), followed by the percent of the population coded to "non-Hispanic, some other race" (ß = -2.59, p < 0.0023), and the percent of families in poverty (ß = -0.26, p < 0.0001). Percent of the population was non-Hispanic American Indian/Alaskan Native (ß = 0.35, p < 0.0001) and percent non-Hispanic Asian (ß = 0.12, p < 0.02071) were associated with higher TPS. Lower predicted TPS was observed in large urban cities throughout the US as well as in states throughout the Southeastern US. Similar geographic patterns were observed for the predicted Patient Safety, Person and Community Engagement, and Efficiency and Cost Reduction domain scores but are not for predicted Clinical Outcomes scores. CONCLUSIONS: The lower predicted scores seen in cities and in the Southeastern region potentially reflect an inherent-that is, structural-association between market sociodemographics and HVBP scores.

Short-Term Mortality Associated with Outpatient Vascular Access Restoration Procedures.

This study confirms the safety of endovascular interventions for thrombosis of hemodialysis access in outpatient and office-based settings.Risk of death in the week after vascular access procedure was not associated with hemodialysis access type (fistula versus graft).

Scent of a human: The mosquito olfactory system defies dogma to ensure attraction to humans.

Mosquitoes are strongly attracted to humans, and their bites not only cause intense itch but can beget severe diseases. In this issue of Cell, Herre et al. reveal that non-canonical olfactory circuit organization and coding likely endow mosquitoes with a robust ability to locate human hosts.

Motor function and safety after allogeneic cord blood and cord tissue-derived mesenchymal stromal cells in cerebral palsy: An open-label, randomized trial.

AIM: To evaluate safety and motor function after treatment with allogeneic umbilical cord blood (AlloCB) or umbilical cord tissue-derived mesenchymal stromal cells (hCT-MSC) in children with cerebral palsy (CP). METHOD: Ninety-one children (52 males, 39 females; median age 3 years 7 months [range 2-5 years]) with CP due to hypoxic-ischemic encephalopathy, stroke, or periventricular leukomalacia were randomized to three arms: (1) the AlloCB group received 10 × 107 AlloCB total nucleated cells (TNC) per kilogram at baseline (n = 31); (2) the hCT-MSC group received 2 × 106 hCT-MSC at baseline, 3 months, and 6 months (n = 28); (3) the natural history control group received 10 × 107 AlloCB TNC per kilogram at 12 months (n = 31). Motor function was assessed with the Gross Motor Function Measure-66 (GMFM-66) and Peabody Developmental Motor Scale, Second Edition. RESULTS: Infusions (n = 143) were well tolerated, with eight infusion reactions (three in the AlloCB group, five in hCT-MSC) and no other safety concerns. At 12 months, the mean differences (95% confidence intervals [CI]) between actual and expected changes in GMFM-66 score were AlloCB 5.8 points (3.4-8.2), hCT-MSC 4.3 (2.2-6.4), and natural history 3.1 (1.4-5.0). In exploratory, post hoc analysis, the mean GMFM-66 score (95% CI) of the hCT-MSC group was 1.4 points higher than natural history (-1.1 to 4.0; p = 0.27), and the AlloCB group was 3.3 points higher than natural history (0.59-5.93; p = 0.02) after adjustment for baseline Gross Motor Function Classification System level, GMFM-66 score, and etiology. INTERPRETATION: High-dose AlloCB is a potential cell therapy for CP and should be further tested in a randomized, blinded, placebo-controlled trial. WHAT THIS PAPER ADDS: Unrelated donor allogeneic umbilical cord blood (AlloCB) and human umbilical cord tissue-derived mesenchymal stromal cell infusion is safe in young children with cerebral palsy. Significant changes in motor function were not observed 6 months after treatment. One year later, treatment with AlloCB was associated with greater increases in Gross Motor Function Measure-66 scores.

Divergent signaling requirements of dSARM in injury-induced degeneration and developmental glial phagocytosis.

Elucidating signal transduction mechanisms of innate immune pathways is essential to defining how they elicit distinct cellular responses. Toll-like receptors (TLR) signal through their cytoplasmic TIR domains which bind other TIR domain-containing adaptors. dSARM/SARM1 is one such TIR domain adaptor best known for its role as the central axon degeneration trigger after injury. In degeneration, SARM1's domains have been assigned unique functions: the ARM domain is auto-inhibitory, SAM-SAM domain interactions mediate multimerization, and the TIR domain has intrinsic NAD+ hydrolase activity that precipitates axonal demise. Whether and how these distinct functions contribute to TLR signaling is unknown. Here we show divergent signaling requirements for dSARM in injury-induced axon degeneration and TLR-mediated developmental glial phagocytosis through analysis of new knock-in domain and point mutations. We demonstrate intragenic complementation between reciprocal pairs of domain mutants during development, providing evidence for separability of dSARM functional domains in TLR signaling. Surprisingly, dSARM's NAD+ hydrolase activity is strictly required for both degenerative and developmental signaling, demonstrating that TLR signal transduction requires dSARM's enzymatic activity. In contrast, while SAM domain-mediated dSARM multimerization is important for axon degeneration, it is dispensable for TLR signaling. Finally, dSARM functions in a linear genetic pathway with the MAP3K Ask1 during development but not in degenerating axons. Thus, we propose that dSARM exists in distinct signaling states in developmental and pathological contexts.

Isolation and RNA sequencing of single nuclei from Drosophila tissues.

Many insect cells are encapsulated within the exoskeleton and cannot be dissociated intact, making them inaccessible to single-cell transcriptomic profiling. We have used single-nucleus RNA sequencing to extract transcriptomic information from multiple Drosophila tissues. Here, we describe procedures for the (1) dissociation of single nuclei, (2) isolation of single nuclei using two popular cell sorters, and (3) preparation of libraries for Smart-seq2 and 10× Genomics. This protocol enables generation of high-quality transcriptomes from single nuclei and can be applied to other species. For complete details on the use and execution of this protocol, please refer to McLaughlin et al. (2021) and Li et al. (2022).

Fly Cell Atlas: A single-nucleus transcriptomic atlas of the adult fruit fly.

For more than 100 years, the fruit fly Drosophila melanogaster has been one of the most studied model organisms. Here, we present a single-cell atlas of the adult fly, Tabula Drosophilae, that includes 580,000 nuclei from 15 individually dissected sexed tissues as well as the entire head and body, annotated to >250 distinct cell types. We provide an in-depth analysis of cell type-related gene signatures and transcription factor markers, as well as sexual dimorphism, across the whole animal. Analysis of common cell types between tissues, such as blood and muscle cells, reveals rare cell types and tissue-specific subtypes. This atlas provides a valuable resource for the Drosophila community and serves as a reference to study genetic perturbations and disease models at single-cell resolution.

Sex differences in associations between birth characteristics and childhood cancers: a five-state registry-linkage study.

BACKGROUND: There is a well-recognized male excess in childhood cancer incidence; however, it is unclear whether there is etiologic heterogeneity by sex when defined by epidemiologic risk factors. METHODS: Using a 5-state registry-linkage study (cases n = 16,411; controls n = 69,816), we estimated sex-stratified odds ratios (OR) and 95% confidence intervals (95% CI) between birth and demographic characteristics for 16 pediatric cancers. Evidence of statistical interaction (p-interaction < 0.01) by sex was evaluated for each characteristic in each cancer. RESULTS: Males comprised > 50% of cases for all cancers, except Wilms tumor (49.6%). Sex interacted with a number of risk factors (all p-interaction < 0.01) including gestational age for ALL (female, 40 vs. 37-39 weeks OR: 0.84, 95% CI 0.73-0.97) and ependymoma (female, 40 vs. 37-39 OR: 1.78, 95% CI 1.14-2.79; female, ≥ 41 OR: 2.01. 95% CI 1.29-3.14), birth order for AML (female, ≥ 3rd vs. 1st OR: 1.39, 95% CI 1.01-1.92), maternal education for Hodgkin lymphoma (male, any college vs. < high school[HS] OR: 1.47, 95% CI 1.03-2.09) and Wilms tumor (female, any college vs. HS OR: 0.74, 95% CI 0.59-0.93), maternal race/ethnicity for neuroblastoma (male, black vs. white OR: 2.21, 95% CI 1.21-4.03; male, Hispanic vs. white OR: 1.86, 95% CI 1.26-2.75; female, Asian/Pacific Islander vs. white OR: 0.28, 95% CI 0.12-0.69), and paternal age (years) for hepatoblastoma in males (< 24 vs. 25-29 OR: 2.17, 95% CI 1.13-4.19; ≥ 35 vs. 25-29 OR: 2.44, 95% CI 1.28-4.64). CONCLUSIONS: These findings suggest etiologic heterogeneity by sex for childhood cancers for gestational age, maternal education, and race/ethnicity and paternal age.

Evaluation of Cell-Based and Surrogate SARS-CoV-2 Neutralization Assays.

Determinants of protective immunity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection require the development of well-standardized, reproducible antibody assays. This need has led to the emergence of a variety of neutralization assays. Head-to-head evaluation of different SARS-CoV-2 neutralization platforms could facilitate comparisons across studies and laboratories. Five neutralization assays were compared using 40 plasma samples from convalescent individuals with mild to moderate coronavirus disease 2019 (COVID-19): four cell-based systems using either live recombinant SARS-CoV-2 or pseudotyped viral particles created with lentivirus (LV) or vesicular stomatitis virus (VSV) packaging and one surrogate enzyme-linked immunosorbent assay (ELISA)-based test that measures inhibition of the spike protein receptor binding domain (RBD) binding its receptor human angiotensin converting enzyme 2 (hACE2). Vero cells, Vero E6 cells, HEK293T cells expressing hACE2, and TZM-bl cells expressing hACE2 and transmembrane serine protease 2 were tested. All cell-based assays showed 50% neutralizing dilution (ND50) geometric mean titers (GMTs) that were highly correlated (Pearson r = 0.81 to 0.89) and ranged within 3.4-fold. The live virus assay and LV pseudovirus assays with HEK293T/hACE2 cells showed very similar mean titers, 141 and 178, respectively. ND50 titers positively correlated with plasma IgG targeting SARS-CoV-2 spike protein and RBD (r = 0.63 to 0.89), but moderately correlated with nucleoprotein IgG (r = 0.46 to 0.73). ND80 GMTs mirrored ND50 data and showed similar correlation between assays and with IgG concentrations. The VSV pseudovirus assay and LV pseudovirus assay with HEK293T/hACE2 cells in low- and high-throughput versions were calibrated against the WHO SARS-CoV-2 IgG standard. High concordance between the outcomes of cell-based assays with live and pseudotyped virions enables valid cross-study comparison using these platforms.

Sibling umbilical cord blood infusion is safe in young children with cerebral palsy.

Preclinical and early phase clinical studies suggest that an appropriately dosed umbilical cord blood (CB) infusion has the potential to help improve motor function in young children with cerebral palsy (CP). As many children with CP do not have their own CB available, use of allogeneic cells would extend access to this potentially beneficial therapy to more children. In this phase I, open-label study, 15 children, aged 1 to 6 years, with moderate to severe spastic CP were treated with a single intravenous infusion of allogeneic human leukocyte antigen (HLA) matched or partially matched sibling CB with a cell dose of ≥2.5 × 107 cells/kg based on the pre-cryopreservation count (median infused cell dose, 3.3 × 107 ; range, 1.8-5.2 × 107 ). There were a total of 49 adverse events (AEs) over a 2-year time period, but there were no AEs related to the CB infusions. Specifically, there were no acute infusion reactions and no antibody formation against platelets, red blood cells, or donor-specific HLA antigens. Donor cells were not detected in peripheral blood 6 months later. Six months after infusion, participants were assessed for response and experienced a mean ± SD increase of 4.7 ± 2.5 points on the Gross Motor Function Measure-66 and 1 ± 2.9 points on the Peabody Gross Motor Quotient. Appropriately dosed, allogeneic partially or fully HLA-matched sibling CB infusion is well tolerated and potentially beneficial in young children with CP.

Napabucasin Drug-Drug Interaction Potential, Safety, Tolerability, and Pharmacokinetics Following Oral Dosing in Healthy Adult Volunteers.

Napabucasin is an orally administered reactive oxygen species generator that is bioactivated by the intracellular antioxidant nicotinamide adenine dinucleotide phosphate:quinone oxidoreductase 1. Napabucasin induces cell death in cancer cells, including cancer stem cells. This phase 1 study (NCT03411122) evaluated napabucasin drug-drug interaction potential for 7 cytochrome P450 (CYP) enzymes and the breast cancer resistance protein transporter/organic anion transporter 3. Healthy volunteers who tolerated napabucasin during period 1 received probe drugs during period 2, and in period 3 received napabucasin (240 mg twice daily; days 1-11) plus a phenotyping cocktail containing omeprazole (CYP2C19), caffeine (CYP1A2), flurbiprofen (CYP2C9), bupropion (CYP2B6), dextromethorphan (CYP2D6), midazolam (CYP3A) (all oral; day 6), intravenous midazolam (day 7), repaglinide (CYP2C8; day 8), and rosuvastatin (breast cancer resistance protein/organic anion transporter 3; day 9). Drug-drug interaction potential was evaluated in 17 of 30 enrolled volunteers. Napabucasin coadministration increased the area under the plasma concentration-time curve from time 0 extrapolated to infinity (geometric mean ratio [90% confidence interval]) of caffeine (124% [109.0%-141.4%]), intravenous midazolam (118% [94.4%-147.3%]), repaglinide (127% [104.7%-153.3%]), and rosuvastatin (213% [42.5%-1068.3%]) and decreased the area under the plasma concentration-time curve from time 0 extrapolated to infinity of dextromethorphan (71% [47.1%-108.3%]), bupropion (79% [64.6%-97.0%]), and hydroxybupropion (45% [15.7%-129.6%]). No serious adverse events/deaths were reported. Generally, napabucasin is not expected to induce/inhibit drug clearance to a clinically meaningful degree.

Single-cell transcriptomes of developing and adult olfactory receptor neurons in Drosophila.

Recognition of environmental cues is essential for the survival of all organisms. Transcriptional changes occur to enable the generation and function of the neural circuits underlying sensory perception. To gain insight into these changes, we generated single-cell transcriptomes of Drosophila olfactory- (ORNs), thermo-, and hygro-sensory neurons at an early developmental and adult stage using single-cell and single-nucleus RNA sequencing. We discovered that ORNs maintain expression of the same olfactory receptors across development. Using receptor expression and computational approaches, we matched transcriptomic clusters corresponding to anatomically and physiologically defined neuron types across multiple developmental stages. We found that cell-type-specific transcriptomes partly reflected axon trajectory choices in development and sensory modality in adults. We uncovered stage-specific genes that could regulate the wiring and sensory responses of distinct ORN types. Collectively, our data reveal transcriptomic features of sensory neuron biology and provide a resource for future studies of their development and physiology.

Temporal evolution of single-cell transcriptomes of Drosophila olfactory projection neurons.

Neurons undergo substantial morphological and functional changes during development to form precise synaptic connections and acquire specific physiological properties. What are the underlying transcriptomic bases? Here, we obtained the single-cell transcriptomes of Drosophila olfactory projection neurons (PNs) at four developmental stages. We decoded the identity of 21 transcriptomic clusters corresponding to 20 PN types and developed methods to match transcriptomic clusters representing the same PN type across development. We discovered that PN transcriptomes reflect unique biological processes unfolding at each stage-neurite growth and pruning during metamorphosis at an early pupal stage; peaked transcriptomic diversity during olfactory circuit assembly at mid-pupal stages; and neuronal signaling in adults. At early developmental stages, PN types with adjacent birth order share similar transcriptomes. Together, our work reveals principles of cellular diversity during brain development and provides a resource for future studies of neural development in PNs and other neuronal types.

Evaluation of SARS-CoV-2 neutralization assays for antibody monitoring in natural infection and vaccine trials.

Determinants of protective immunity against SARS-CoV-2 infection require the development of well-standardized, reproducible antibody assays to be utilized in concert with clinical trials to establish correlates of risk and protection. This need has led to the appearance of a variety of neutralization assays used by different laboratories and companies. Using plasma samples from COVID-19 convalescent individuals with mild-to-moderate disease from a localized outbreak in a single region of the western US, we compared three platforms for SARS-CoV-2 neutralization: assay with live SARS-CoV-2, pseudovirus assay utilizing lentiviral (LV) and vesicular stomatitis virus (VSV) packaging, and a surrogate ELISA test. Vero, Vero E6, HEK293T cells expressing human angiotensin converting enzyme 2 (hACE2), and TZM-bl cells expressing hACE2 and transmembrane serine protease 2 (TMPRSS2) were evaluated. Live-virus and LV-pseudovirus assay with HEK293T cells showed similar geometric mean titers (GMTs) ranging 141-178, but VSV-pseudovirus assay yielded significantly higher GMT (310 95%CI 211-454; p < 0.001). Fifty percent neutralizing dilution (ND50) titers from live-virus and all pseudovirus assay readouts were highly correlated (Pearson r = 0.81-0.89). ND50 titers positively correlated with plasma concentration of IgG against SARS-CoV-2 spike and receptor binding domain (RBD) ( r = 0.63-0.89), but moderately correlated with nucleoprotein IgG ( r = 0.46-0.73). There was a moderate positive correlation between age and spike (Spearman's rho=0.37, p=0.02), RBD (rho=0.39, p=0.013) and nucleoprotein IgG (rho=0.45, p=0.003). ND80 showed stronger correlation with age than ND50 (ND80 rho=0.51 (p=0.001), ND50 rho=0.28 (p=0.075)). Our data demonstrate high concordance between cell-based assays with live and pseudotyped virions.

High Community SARS-CoV-2 Antibody Seroprevalence in a Ski Resort Community, Blaine County, Idaho, US. Preliminary Results.

Community-level seroprevalence surveys are needed to determine the proportion of the population with previous SARS-CoV-2 infection, a necessary component of COVID-19 disease surveillance. In May, 2020, we conducted a cross-sectional seroprevalence study of IgG antibodies for nucleocapsid of SARS-CoV-2 among the residents of Blaine County, Idaho, a ski resort community with high COVID-19 attack rates in late March and Early April (2.9% for ages 18 and older). Participants were selected from volunteers who registered via a secure web link, using prestratification weighting to the population distribution by age and gender within each ZIP Code. Participants completed a survey reporting their demographics and symptoms; 88% of volunteers who were invited to participate completed data collection survey and had 10 ml of blood drawn. Serology was completed via the Abbott Architect SARS-CoV-2 IgG immunoassay. Primary analyses estimated seroprevalence and 95% credible intervals (CI) using a hierarchical Bayesian framework to account for diagnostic uncertainty. Stratified models were run by age, sex, ZIP Code, ethnicity, employment status, and a priori participant-reported COVID-19 status. Sensitivity analyses to estimate seroprevalence included base models with post-stratification for ethnicity, age, and sex, with or without adjustment for multi-participant households. IgG antibodies to the virus that causes COVID-19 were found among 22.7% (95% CI: 20.1%, 25.5%) of residents of Blaine County. Higher levels of antibodies were found among residents of the City of Ketchum 34.8% (95% CI 29.3%, 40.5%), compared to Hailey 16.8% (95%CI 13.7%, 20.3%) and Sun Valley 19.4% (95% 11.8%, 28.4%). People who self-identified as not believing they had COVID-19 had the lowest prevalence 4.8% (95% CI 2.3%, 8.2%). The range of seroprevalence after correction for potential selection bias was 21.9% to 24.2%. This study suggests more than 80% of SARS-CoV-2 infections were not reported. Although Blaine County had high levels of SARS-CoV-2 infection, the community is not yet near the herd immunity threshold.

Infusion of human umbilical cord tissue mesenchymal stromal cells in children with autism spectrum disorder.

Ongoing neuroinflammation may contribute to symptoms of autism spectrum disorder (ASD) in at least a portion of affected individuals. Mesenchymal stromal cells (MSCs) have demonstrated the capacity to modulate neuroinflammation, but safety and feasibility of MSC administration in children with ASD have not been well established. In this open-label, phase I study, 12 children with ASD between 4 and 9 years of age were treated with intravenous (IV) infusions of human cord tissue mesenchymal stromal cells (hCT-MSCs), a third-party MSC product manufactured from unrelated donor umbilical cord tissue. Children received one, two, or three doses of 2 × 106 cells per kilogram at 2-month intervals. Clinical and laboratory evaluations were performed in person at baseline and 6 months and remotely at 12 months after the final infusion. Aside from agitation during the IV placement and infusion in some participants, hCT-MSCs were well tolerated. Five participants developed new class I anti-human leukocyte antigen (HLA) antibodies, associated with a specific lot of hCT-MSCs or with a partial HLA match between donor and recipient. These antibodies were clinically silent and not associated with any clinical manifestations to date. Six of 12 participants demonstrated improvement in at least two ASD-specific measures. Manufacturing and administration of hCT-MSCs appear to be safe and feasible in young children with ASD. Efficacy will be evaluated in a subsequent phase II randomized, placebo-controlled clinical trial.

Single-Cell Transcriptomes Reveal Diverse Regulatory Strategies for Olfactory Receptor Expression and Axon Targeting.

The regulatory mechanisms by which neurons coordinate their physiology and connectivity are not well understood. The Drosophila olfactory receptor neurons (ORNs) provide an excellent system to investigate this question. Each ORN type expresses a unique olfactory receptor, or a combination thereof, and sends their axons to a stereotyped glomerulus. Using single-cell RNA sequencing, we identified 33 transcriptomic clusters for ORNs and mapped 20 to their glomerular types, demonstrating that transcriptomic clusters correspond well with anatomically and physiologically defined ORN types. Each ORN type expresses hundreds of transcription factors. Transcriptome-instructed genetic analyses revealed that (1) one broadly expressed transcription factor (Acj6) only regulates olfactory receptor expression in one ORN type and only wiring specificity in another type, (2) one type-restricted transcription factor (Forkhead) only regulates receptor expression, and (3) another type-restricted transcription factor (Unplugged) regulates both events. Thus, ORNs utilize diverse strategies and complex regulatory networks to coordinate their physiology and connectivity.

Cell-Surface Proteomic Profiling in the Fly Brain Uncovers Wiring Regulators.

Molecular interactions at the cellular interface mediate organized assembly of single cells into tissues and, thus, govern the development and physiology of multicellular organisms. Here, we developed a cell-type-specific, spatiotemporally resolved approach to profile cell-surface proteomes in intact tissues. Quantitative profiling of cell-surface proteomes of Drosophila olfactory projection neurons (PNs) in pupae and adults revealed global downregulation of wiring molecules and upregulation of synaptic molecules in the transition from developing to mature PNs. A proteome-instructed in vivo screen identified 20 cell-surface molecules regulating neural circuit assembly, many of which belong to evolutionarily conserved protein families not previously linked to neural development. Genetic analysis further revealed that the lipoprotein receptor LRP1 cell-autonomously controls PN dendrite targeting, contributing to the formation of a precise olfactory map. These findings highlight the power of temporally resolved in situ cell-surface proteomic profiling in discovering regulators of brain wiring.