A short amphipathic alpha helix in scavenger receptor BI facilitates bidirectional HDL-cholesterol transport.

During reverse cholesterol transport, high-density lipoprotein (HDL) carries excess cholesterol from peripheral cells to the liver for excretion in bile. The first and last steps of this pathway involve the HDL receptor, scavenger receptor BI (SR-BI). While the mechanism of SR-BI-mediated cholesterol transport has not yet been established, it has long been suspected that cholesterol traverses through a hydrophobic tunnel in SR-BI's extracellular domain. Confirmation of a hydrophobic tunnel is hindered by the lack of a full-length SR-BI structure. Part of SR-BI's structure has been resolved, encompassing residues 405 to 475, which includes the C-terminal transmembrane domain and its adjacent extracellular region. Within the extracellular segment is an amphipathic helix (residues 427-436, referred to as AH(427-436)) that showed increased protection from solvent in NMR-based studies. Homology models predict that hydrophobic residues in AH(427-436) line a core cavity in SR-BI's extracellular region that may facilitate cholesterol transport. Therefore, we hypothesized that hydrophobic residues in AH(427-436) are required for HDL cholesterol transport. Here, we tested this hypothesis by mutating individual residues along AH(427-436) to a charged residue (aspartic acid), transiently transfecting COS-7 cells with plasmids encoding wild-type and mutant SR-BI, and performing functional analyses. We found that mutating hydrophobic, but not hydrophilic, residues in AH(427-436) impaired SR-BI bidirectional cholesterol transport. Mutating phenylalanine-430 was particularly detrimental to SR-BI's functions, suggesting that this residue may facilitate important interactions for cholesterol delivery within the hydrophobic tunnel. Our results support the hypothesis that a hydrophobic tunnel within SR-BI mediates cholesterol transport.

Venous thromboembolism risk in cancer patients receiving first-line immune checkpoint inhibitor versus chemotherapy.

It remains unclear if immune checkpoint inhibitor (ICI) therapy is associated with higher rate of venous thromboembolism (VTE) compared with cytotoxic chemotherapy (chemo) in patients with comparable cancer type, staging, and comorbidities. Using the national Veterans Affairs healthcare system database from 2016 to 2021, we performed a propensity score (PS)-weighted retrospective cohort study to compare the incidence of VTE in patients with selected stage III/IV cancer receiving first-line ICI versus chemo. The PS model utilized overlap weights to balance age, sex, race, treatment year, VTE history, paralysis/immobilization, prolonged hospitalization, cancer type, staging, time between diagnosis and treatment, and National Cancer Institute comorbidity index. Weighted Cox regressions with robust standard error were used to assess the hazard ratio (HR) and 95% confidence interval (CI). We found that among comparable advanced cancers, first-line ICI (n = 1823) and first-line chemo (n = 6345) had similar rates of VTE (8.49% for ICI and 8.36% for chemo at 6 months). The weighted HR was 1.06 (95% CI 0.88-1.26) for ICI versus chemo. In a subgroup analysis restricted to lung cancers, first-line ICI/chemo (n = 828), ICI monotherapy (n = 428), and chemo monotherapy (n = 4371) had similar rates of VTE (9.60% for ICI/chemo, 10.04% for ICI, and 8.91% for chemo at 6 months). The weighted HR was 1.05 (95% CI 0.77-1.42) for ICI versus chemo, and 1.08 (95% CI 0.83-1.42) for ICI/chemo versus chemo. In conclusion, ICI as a systemic therapy has a similarly elevated risk as cytotoxic chemo for VTE occurrence in cancer patients. This finding can inform future prospective studies exploring thromboprophylaxis strategies.

Impact of routine urine cultures on antibiotic usage in those undergoing a routine annual spinal cord injury evaluation.

OBJECTIVE: The Veterans Health Administration (VHA), the largest single provider of spinal cord injury and disorder (SCI/D) care in the United States, currently mandates that every patient receives a screening urine culture during the annual evaluation, a yearly comprehensive history and physical examination. This testing has shown in a small subset of patients to overidentify asymptomatic bacteriuria that is then inappropriately treated with antibiotics. The objective of the current analysis was to assess the association of the annual evaluation on urine testing and antibiotic treatment in a national sample of Veterans with SCI/D. DESIGN/METHOD: A retrospective cohort study using national VHA electronic health record data of Veterans with SCI/D seen between October 1, 2017-September 30, 2019 for their annual evaluation. RESULTS: There were 9447 Veterans with SCI/D who received an annual evaluation; 5088 (54%) had a urine culture obtained. 2910 cultures (57%) were positive; E. coli was the most common organism obtained (12.9% of total urine cultures). Of the patients with positive urine cultures, 386 were prescribed antibiotics within the 7 days after that encounter (13%); of the patients with negative cultures (n = 2178), 121 (6%) were prescribed antibiotics; thus, a positive urine culture was a significant driver of antibiotic use (p < 0.001). CONCLUSION: The urine cultures ordered at the annual exam are often followed by antibiotics; this practice may be an important target for antibiotic stewardship programs in SCI.

Non-Alcoholic Fatty Liver Disease: Translating Disease Mechanisms into Therapeutics Using Animal Models.

Nonalcoholic fatty liver disease (NAFLD) is a range of pathologies arising from fat accumulation in the liver in the absence of excess alcohol use or other causes of liver disease. Its complications include cirrhosis and liver failure, hepatocellular carcinoma, and eventual death. NAFLD is the most common cause of liver disease globally and is estimated to affect nearly one-third of individuals in the United States. Despite knowledge that the incidence and prevalence of NAFLD are increasing, the pathophysiology of the disease and its progression to cirrhosis remain insufficiently understood. The molecular pathogenesis of NAFLD involves insulin resistance, inflammation, oxidative stress, and endoplasmic reticulum stress. Better insight into these molecular pathways would allow for therapies that target specific stages of NAFLD. Preclinical animal models have aided in defining these mechanisms and have served as platforms for screening and testing of potential therapeutic approaches. In this review, we will discuss the cellular and molecular mechanisms thought to contribute to NAFLD, with a focus on the role of animal models in elucidating these mechanisms and in developing therapies.

Pcpe2, a Novel Extracellular Matrix Protein, Regulates Adipocyte SR-BI-Mediated High-Density Lipoprotein Uptake.

Objective: To investigate the role of adipocyte Pcpe2 (procollagen C-endopeptidase enhancer 2) in SR-BI (scavenger receptor class BI)-mediated HDL-C (high-density lipoprotein cholesterol) uptake and contributions to adipose lipid storage. Approach and Results: Pcpe2, a glycoprotein devoid of intrinsic proteolytic activity, is believed to participate in extracellular protein-protein interactions, supporting SR-BI- mediated HDL-C uptake. In published studies, Pcpe2 deficiency increased the development of atherosclerosis by reducing SR-BI-mediated HDL-C catabolism, but the biological impact of this deficiency on adipocyte SR-BI-mediated HDL-C uptake is unknown. Differentiated cells from Ldlr-/-/Pcpe2-/- (Pcpe2-/-) mouse adipose tissue showed elevated SR-BI protein levels, but significantly reduced HDL-C uptake compared to Ldlr-/- (control) adipose tissue. SR-BI-mediated HDL-C uptake was restored by preincubation of cells with exogenous Pcpe2. In diet-fed mice lacking Pcpe2, significant reductions in visceral, subcutaneous, and brown adipose tissue mass were observed, despite elevations in plasma triglyceride and cholesterol concentrations. Significant positive correlations exist between adipose mass and Pcpe2 expression in both mice and humans. Conclusions: Overall, these findings reveal a novel and unexpected function for Pcpe2 in modulating SR-BI expression and function as it relates to adipose tissue expansion and cholesterol balance in both mice and humans.

Human variant of scavenger receptor BI (R174C) exhibits impaired cholesterol transport functions.

HDL and its primary receptor, scavenger receptor class B type I (SR-BI), work together to promote the clearance of excess plasma cholesterol, thereby protecting against atherosclerosis. Human variants of SR-BI have been identified in patients with high HDL-cholesterol levels, and at least one variant has been linked to cardiovascular disease. Therefore, while often regarded as beneficial, very high levels of HDL-cholesterol may result from impaired cholesterol clearance through SR-BI and contribute to cardiovascular risk. In this study, we characterized the function of a rare human variant of SR-BI, resulting in the substitution of arginine-174 with cysteine (R174C), which was previously identified in a heterozygous individual with high levels of HDL-cholesterol. We hypothesized that the R174C-SR-BI variant has impaired cholesterol transport functions, which were assessed in COS-7 cells after transient transfection with full-length WT or R174C-SR-BI. Although R174C-SR-BI was expressed at levels comparable to the WT receptor, HDL binding, cholesteryl hexadecyl ether uptake, free cholesterol efflux, and modulation of membrane cholesterol were disrupted in the presence of R174C-SR-BI. We further examined the role of salt bridges as a potential mechanism for R174C-SR-BI dysfunction. If translatable, this human variant could lead to increased plasma HDL-cholesterol levels, impaired cholesterol clearance, and increased cardiovascular disease risk.

Cause-and-Effect Analysis as a Tool To Improve the Reproducibility of Nanobioassays: Four Case Studies.

One of the challenges in using in vitro data to understand the potential risks of engineered nanomaterials (ENMs) is that results often differ or are even contradictory among studies. While it is recognized that numerous factors can influence results produced by nanobioassays, there has not yet been a consistently used conceptual framework to identify key sources of variability in these assays. In this paper, we use cause-and-effect analysis to systematically describe sources of variability in four key in vitro nanobioassays: the 2',7'-dichlorofluorescein assay, an enzyme-linked immunosorbent assay for measuring interleukin-8, a flow cytometry assay (Annexin V/propidium iodide), and the Comet assay. These assays measure end points that can occur in cells impacted by ENMs through oxidative stress, a principle mechanism for ENM toxicity. The results from this analysis identify control measurements to test for potential artifacts or biases that could occur during conduct of these assays with ENMs. Cause-and-effect analysis also reveals additional measurements that could be performed either in preliminary experiments or each time the assay is run to increase confidence in the assay results and their reproducibility within and among laboratories. The approach applied here with these four assays can be used to support the development of a broad range of nanobioassays.

Retrospective analysis of long-term outcome 10 years after liver transplantation for Wilson disease: experience over three decades.

We evaluated long-term outcomes for patients with Wilson disease (WD) after liver transplantation (LT) and searched for risk factors for poor survival. Retrospective analysis of UNOS/OPTN data identified 156 pediatric and 515 adult cases of LT for WD between 1987 and 2016. Comparison cases were 10 442 pediatric and 104 874 adult non-WD transplant recipients. Survival was calculated using Kaplan-Meier analysis. Recipient, donor, and surgical variables were compared by Cox regression. Survival rates 3, 5, and 10 years after LT for adult WD patients (87.5%, 85.4%, and 80.5%, respectively) were significantly higher than those for non-WD patients (P < 0.001); survival rates for pediatric WD patients (90.5%, 89.7%, and 86.5%, respectively) did not differ significantly from non-WD patients. Graft survival in adult and pediatric patients followed similar trends. Regression analysis identified older age, female gender, and use of life support at the time of transplant as risk factors for decreased survival for adults with WD, and younger age, male gender, obesity, and high serum creatinine at the time of transplant as risk factors for poor survival in pediatric recipients with WD. Presentation with fulminant liver failure was not associated with survival in WD patients. No donor characteristic predicted poor survival. Long-term patient and graft survival after LT is excellent for both adult and pediatric WD patients.

Social cognitive predictors of engineering students' academic persistence intentions, satisfaction, and engagement.

The demand for high quality engineers is of particular importance as engineering jobs are projected to grow in the next 10 years (United States Bureau of Labor Statistics, 2018). More work is needed to understand factors related to academic engagement, satisfaction, and persistence intentions of Latino/as and women in engineering: 2 underrepresented groups in the engineering pipeline. We present findings that explored the role of social-cognitive, environmental, and personality variables in engineering persistence intentions, engagement and satisfaction of a diverse sample of 1,335 engineering students using an extension of the integrative social cognitive career theory model (SCCT; Lent et al., 2013). Results indicated that (a) the hypothesized model fit the data well for the full sample and across 8 subsamples based on gender-ethnicity (i.e., Latinas, Latinos, White women, and White men) and ethnicity-school type (i.e., Latina/os at Hispanic-serving institutions [HSIs], Latina/os at predominantly White institutions [PWIs], Whites at HSIs, and Whites at PWIs), (b) all but 5 model parameters were significant and positive for the full sample, (c) a subset of model parameters differed by the interactions of race/ethnicity-gender and race/ethnicity-school type groups, and (d) the relations within the model explained a significant amount of variance in engineering academic engagement, satisfaction, and persistence intentions for the full sample and 8 subsamples. Implications of the findings for educational and career interventions aimed at retaining Latina/os and women in engineering are discussed in relation to building on social cognitions in engineering academic engagement, satisfaction, and persistence intentions. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Hepatocellular Carcinoma in the Absence of Cirrhosis in United States Veterans is Associated With Nonalcoholic Fatty Liver Disease.

BACKGROUND & AIMS: Hepatocellular carcinoma (HCC) can develop in individuals without cirrhosis. We investigated risk factors for development of HCC in the absence of cirrhosis in a U.S. METHODS: We identified a national cohort of 1500 patients with verified HCC during 2005 to 2010 in the U.S. Veterans Administration (VA) and reviewed their full VA medical records for evidence of cirrhosis and risk factors for HCC. Patients without cirrhosis were assigned to categories of level 1 evidence for no cirrhosis (very high probability) or level 2 evidence for no cirrhosis (high probability), which were based on findings from histologic analyses, laboratory test results, markers of fibrosis from noninvasive tests, and imaging features. RESULTS: A total of 43 of the 1500 patients with HCC (2.9%) had level 1 evidence for no cirrhosis, and 151 (10.1%) had level 2 evidence for no cirrhosis; the remaining 1203 patients (80.1%) had confirmed cirrhosis. Compared with patients with HCC in presence of cirrhosis, greater proportions of patients with HCC without evidence of cirrhosis had metabolic syndrome, nonalcoholic fatty liver disease (NAFLD), or no identifiable risk factors. Patients with HCC without evidence of cirrhosis were less likely to have abused alcohol or have hepatitis C virus infection than patients with cirrhosis. Patients with HCC and NAFLD (unadjusted odds ratio, 5.4; 95% confidence interval, 3.4-8.5) or metabolic syndrome (unadjusted odds ratio, 5.0; 95% confidence interval, 3.1-7.8) had more than 5-fold risk of having HCC in the absence of cirrhosis, compared with patients with HCV-related HCC. CONCLUSIONS: Approximately 13% of patients with HCC in the VA system do not appear to have cirrhosis. NAFLD and metabolic syndrome are the main risk factors for HCC in the absence of cirrhosis.

Transarterial bland versus chemoembolization for hepatocellular carcinoma: rethinking a gold standard.

BACKGROUND: Transarterial chemoembolization (TACE) is the most common procedure for the treatment of hepatocellular carcinoma (HCC). However, HCC is generally considered chemoresistant and data demonstrating the superiority of TACE over bland embolization (TAE) are lacking. MATERIALS AND METHODS: A nationwide, retrospective cohort study of HCC patients treated with first-line TACE or TAE within the Veterans Affairs health care system (2005-2012) was performed. The primary outcome was overall survival. Risk of death by treatment type (TACE or TAE) was evaluated using multivariate (adjusted for age, presence of cirrhosis, Barcelona Clinic Liver Cancer stage, and Charlson comorbidity score) and propensity score-adjusted Cox regression. RESULTS: The cohort included 405 patients treated with first-line transarterial embolization. Among these patients, 32 (7.9%) underwent TAE. Most of the patients (76.8%) had intermediate or advanced stage at presentation. Similar proportions of patients (TACE 53.3% versus TAE 43.7%; P = 0.30) received more than one embolization procedure. There was no difference in median survival (20.1 versus 23.1 mo, respectively; log-rank P = 0.84). Compared to TACE, there was no difference in risk of death associated with TAE after multivariate (hazard ratio [HR] 0.92; 95% CI, 0.61-1.37) and propensity score adjustment (HR = 0.86; 95% CI = 0.58-1.29). CONCLUSIONS: There is no clear benefit associated with chemotherapy infusion over bland embolization for HCC treatment. Given the rising incidence of HCC in the United States and considering the added costs associated with TACE compared to TAE, future work comparing these competing management strategies is needed.

Temporal trends of nonalcoholic fatty liver disease-related hepatocellular carcinoma in the veteran affairs population.

BACKGROUND & AIMS: Nonalcoholic fatty liver disease (NAFLD) is a risk factor for hepatocellular carcinoma (HCC). However, no systemic studies from the United States have examined temporal trends, HCC surveillance practices, and outcomes of NAFLD-related HCC. METHODS: We identified a national cohort of 1500 patients who developed HCC from 2005 through 2010 from Veterans Administration (VA) hospitals. We reviewed patients' full VA medical records; NAFLD was diagnosed based on histologic evidence for, or the presence of, the metabolic syndrome in the absence of hepatitis C virus (HCV) infection, hepatitis B, or alcoholic liver disease. We compared annual prevalence values for the main risk factors (NAFLD, alcohol abuse, and HCV), as well a HCC surveillance and outcomes, among HCC patients. RESULTS: NAFLD was the underlying risk factor for HCC in 120 patients (8.0%); the annual proportion of NAFLD-related HCC remained relatively stable (7.5%-12.0%). In contrast, the proportion of HCC cases associated with HCV increased from 61.0% in 2005 (95% confidence interval, 53.1%-68.9%) to 74.9% in 2010 (95% confidence interval, 69.0%-80.7%). The proportion of HCC cases associated with only alcohol abuse decreased from 21.9% in 2005 to 15.7% in 2010, and the annual proportion of HCC cases associated with hepatitis B remained relatively stable (1.4%-3.5%). A significantly lower proportion of patients with NAFLD-related HCC had cirrhosis (58.3%) compared with patients with alcohol- or HCV-related HCC (72.4% and 85.6%, respectively; P < .05). A significantly higher percentage of patients with NAFLD-related HCC did not receive HCC surveillance in the 3 years before their HCC diagnosis, compared with patients with alcohol- or HCV-associated HCC. A lower proportion of patients with NAFLD-related HCC received HCC-specific treatment (61.5%) than patients with HCV-related HCC (77.5%; P < .01). However, the 1-year survival rate did not differ among patients with HCC related to different risk factors. CONCLUSIONS: NAFLD is the third most common risk factor for HCC in the VA population. The proportion of NAFLD-related HCC was relatively stable from 2005 through 2010. Although patients with NAFLD-related HCC received less HCC surveillance and treatment, a similar proportion survive for 1 year, compared with patients with alcohol-related or HCV-related HCC.

Generalizable pipeline for constructing HIV risk prediction models across electronic health record systems.

OBJECTIVE: The HIV epidemic remains a significant public health issue in the United States. HIV risk prediction models could be beneficial for reducing HIV transmission by helping clinicians identify patients at high risk for infection and refer them for testing. This would facilitate initiation on treatment for those unaware of their status and pre-exposure prophylaxis for those uninfected but at high risk. Existing HIV risk prediction algorithms rely on manual construction of features and are limited in their application across diverse electronic health record systems. Furthermore, the accuracy of these models in predicting HIV in females has thus far been limited. MATERIALS AND METHODS: We devised a pipeline for automatic construction of prediction models based on automatic feature engineering to predict HIV risk and tested our pipeline on a local electronic health records system and a national claims data. We also compared the performance of general models to female-specific models. RESULTS: Our models obtain similarly good performance on both health record datasets despite difference in represented populations and data availability (AUC = 0.87). Furthermore, our general models obtain good performance on females but are also improved by constructing female-specific models (AUC between 0.81 and 0.86 across datasets). DISCUSSION AND CONCLUSIONS: We demonstrated that flexible construction of prediction models performs well on HIV risk prediction across diverse health records systems and perform as well in predicting HIV risk in females, making deployment of such models into existing health care systems tangible.

Acceptability of a Future HIV Vaccine: A Rapid Scoping Review.

BACKGROUND: A HIV vaccine is not available yet, but perceptions of HIV vaccines will be important to explore before their roll-out for effective vaccine promotion. This article presents the findings of a rapid scoping review of the literature to identify individual, social, and vaccine-related factors associated with the acceptability of a future HIV vaccine. METHODS: We searched 5 databases (Medline OVID, Embase, PsycINFO, Web of Science, and Cochrane) using relevant keywords and Medical Subject Headings. All articles, regardless of study design, publication year, and geographic location, were included if they examined HIV vaccine acceptability and its underlying factors. RESULTS: We retrieved 2386 unique articles, of which 76 were included in the final review. Perceived benefits (34.2%) and perceived susceptibility (25.0%) were primary individual factors of HIV vaccine acceptability. Misinformation (17.1%) and distrust (22.4%) regarding future HIV vaccines, HIV stigma (30.3%), and social support (10.5%) were social factors of HIV vaccine acceptability. Vaccine efficacy (42.1%), cost (28.9%), and side effects (67.1%) were common vaccine characteristics influencing HIV vaccine acceptability. Altruism (10.5%) and risk compensation (26.3%) were also key factors. CONCLUSIONS: Our analyses revealed that skeptical beliefs, negative perceptions, and misconceptions about HIV vaccines are real barriers to their acceptability. To alleviate HIV vaccine hesitancy and address trust concerns, strategic vaccine communication should be disseminated by trustworthy sources. Messages should impart accurate vaccine information and emphasize both individual and social benefits of HIV vaccination, as well as leverage social support in increasing willingness to get a future HIV vaccine.

Discordant Effects of Polyamine Depletion by DENSpm and DFMO on ß-cell Cytokine Stress and Diabetes Outcomes in Mice.

Type 1 diabetes (T1D) is an autoimmune disease leading to dysfunction and loss of insulin-secreting ß cells. In ß cells, polyamines have been implicated in causing cellular stress and dysfunction. An inhibitor of polyamine biosynthesis, difluoromethylornithine (DFMO), has been shown to delay T1D in mouse models and preserve ß-cell function in humans with recent-onset T1D. Another small molecule, N1,N11-diethylnorspermine (DENSpm), both inhibits polyamine biosynthesis and accelerates polyamine metabolism and is being tested for efficacy in cancer clinical trials. In this study, we show that DENSpm depletes intracellular polyamines as effectively as DFMO in mouse ß cells. RNA-sequencing analysis, however, suggests that the cellular responses to DENSpm and DFMO differ, with both showing effects on cellular proliferation but the latter showing additional effects on mRNA translation and protein-folding pathways. In the low-dose streptozotocin-induced mouse model of T1D, DENSpm, unlike DFMO, did not prevent or delay diabetes outcomes but did result in improvements in glucose tolerance and reductions in islet oxidative stress. In nonobese diabetic (NOD) mice, short-term DENSpm administration resulted in a slight reduction in insulitis and proinflammatory Th1 cells in the pancreatic lymph nodes. Longer term treatment resulted in a dose-dependent increase in mortality. Notwithstanding the efficacy of both DFMO and DENSpm in reducing potentially toxic polyamine levels in ß cells, our results highlight the discordant T1D outcomes that result from differing mechanisms of polyamine depletion and, more importantly, that toxic effects of DENSpm may limit its utility in T1D treatment.

Inhibition of the eukaryotic initiation factor-2-α kinase PERK decreases risk of autoimmune diabetes in mice.

Preventing the onset of autoimmune type 1 diabetes (T1D) is feasible through pharmacological interventions that target molecular stress-responsive mechanisms. Cellular stresses, such as nutrient deficiency, viral infection, or unfolded proteins, trigger the integrated stress response (ISR), which curtails protein synthesis by phosphorylating eIF2α. In T1D, maladaptive unfolded protein response (UPR) in insulin-producing beta cells renders these cells susceptible to autoimmunity. We found that inhibition of the eIF2α kinase PERK, a common component of the UPR and ISR, reversed the mRNA translation block in stressed human islets and delayed the onset of diabetes, reduced islet inflammation, and preserved ß cell mass in T1D-susceptible mice. Single-cell RNA sequencing of islets from PERK-inhibited mice showed reductions in the UPR and PERK signaling pathways and alterations in antigen processing and presentation pathways in ß cells. Spatial proteomics of islets from these mice showed an increase in the immune checkpoint protein PD-L1 in ß cells. Golgi membrane protein 1, whose levels increased following PERK inhibition in human islets and EndoC-ßH1 human ß cells, interacted with and stabilized PD-L1. Collectively, our studies show that PERK activity enhances ß cell immunogenicity, and inhibition of PERK may offer a strategy to prevent or delay the development of T1D.

Inhibition of the Eukaryotic Initiation Factor-2-α Kinase PERK Decreases Risk of Autoimmune Diabetes in Mice.

Preventing the onset of autoimmune type 1 diabetes (T1D) is feasible through pharmacological interventions that target molecular stress-responsive mechanisms. Cellular stresses, such as nutrient deficiency, viral infection, or unfolded proteins, trigger the integrated stress response (ISR), which curtails protein synthesis by phosphorylating eIF2α. In T1D, maladaptive unfolded protein response (UPR) in insulin-producing ß cells renders these cells susceptible to autoimmunity. We show that inhibition of the eIF2α kinase PERK, a common component of the UPR and ISR, reverses the mRNA translation block in stressed human islets and delays the onset of diabetes, reduces islet inflammation, and preserves ß cell mass in T1D-susceptible mice. Single-cell RNA sequencing of islets from PERK-inhibited mice shows reductions in the UPR and PERK signaling pathways and alterations in antigen processing and presentation pathways in ß cells. Spatial proteomics of islets from these mice shows an increase in the immune checkpoint protein PD-L1 in ß cells. Golgi membrane protein 1, whose levels increase following PERK inhibition in human islets and EndoC-ßH1 human ß cells, interacts with and stabilizes PD-L1. Collectively, our studies show that PERK activity enhances ß cell immunogenicity, and inhibition of PERK may offer a strategy to prevent or delay the development of T1D.

Protocol to isolate immune cells from mouse pancreatic lymph nodes and whole pancreas for mass cytometric analyses.

Investigating the immune attack on ß cells is critical to understanding autoimmune diabetes. Here, we present a protocol to isolate immune cells from mouse pancreatic lymph nodes and whole pancreas, followed by mass cytometric analyses. This protocol can be used to analyze subsets of innate and adaptive immune cells that play critical roles in autoimmune diabetes, with as few as 5 × 105 cells. This protocol can also be adapted to study resident immune cells from other tissues. For complete details on the use and execution of this protocol, please refer to Piñeros et al. (2022).1.

Epidemiology of Cancer-Associated Venous Thromboembolism in Patients With Solid and Hematologic Neoplasms in the Veterans Affairs Health Care System.

Importance: Identifying changes in epidemiologic patterns of the incidence and risk of cancer-associated thrombosis (CAT), particularly with evolving cancer-directed therapy, is essential for risk stratification. Objective: To assess the incidence of CAT over time and to determine pertinent patient-specific, cancer-specific, and treatment-specific factors associated with its risk. Design, Setting, and Participants: This longitudinal, retrospective cohort study was conducted from 2006 to 2021. Duration of follow-up was from the date of diagnosis until first venous thromboembolism (VTE) event, death, loss of follow-up (defined as a 90-day gap without clinical encounters), or administrative censoring on April 1, 2022. The study took place within the US Department of Veterans Affairs national health care system. Patients with newly diagnosed invasive solid tumors and hematologic neoplasms were included in the study. Data were analyzed from December 2022 to February 2023. Exposure: Newly diagnosed invasive solid tumors and hematologic neoplasms. Main Outcomes: Incidence of VTE was assessed using a combination of International Classification of Diseases, Ninth Revision, Clinical Modification and International Statistical Classification of Diseases, Tenth Revision, Clinical Modification and natural language processing confirmed outcomes. Cumulative incidence competing risk functions were used to estimate incidence of CAT. Multivariable Cox regression models were built to assess the association of baseline variables with CAT. Pertinent patient variables included demographics, region, rurality, area deprivation index, National Cancer Institute comorbidity index, cancer type, staging, first-line systemic treatment within 3 months (time-varying covariate), and other factors that could be associated with the risk of VTE. Results: A total of 434 203 patients (420 244 men [96.8%]; median [IQR] age, 67 [62-74] years; 7414 Asian or Pacific Islander patients [1.7%]; 20 193 Hispanic patients [4.7%]; 89 371 non-Hispanic Black patients [20.6%]; 313 157 non-Hispanic White patients [72.1%]) met the inclusion criteria. Overall incidence of CAT at 12 months was 4.5%, with yearly trends ranging stably from 4.2% to 4.7%. The risk of VTE was associated with cancer type and stage. In addition to confirming well-known risk distribution among patients with solid tumors, a higher risk of VTE was observed among patients with aggressive lymphoid neoplasms compared with patients with indolent lymphoid or myeloid hematologic neoplasms. Compared with no treatment, patients receiving first-line chemotherapy (hazard ratio [HR], 1.44; 95% CI, 1.40-1.49) and immune checkpoint inhibitors (HR, 1.49; 95% CI, 1.22-1.82) had a higher adjusted relative risk than patients receiving targeted therapy (HR, 1.21; 95% CI, 1.13-1.30) or endocrine therapy (HR, 1.20; 95% CI, 1.12-1.28). Finally, adjusted VTE risk was significantly higher among Non-Hispanic Black patients (HR, 1.23; 95% CI, 1.19-1.27) and significantly lower in Asian or Pacific Islander patients (HR, 0.84; 95% CI, 0.76-0.93) compared with Non-Hispanic White patients. Conclusions and Relevance: In this cohort study of patients with cancer, a high incidence of VTE was observed, with yearly trends that remained stable over the 16-year study period. Both novel and known factors associated with the risk of CAT were identified, providing valuable and applicable insights in this current treatment landscape.