Choroid Sprouting Assay: An Ex Vivo Model of Microvascular Angiogenesis

Angiogenesis of the microvasculature is central to the etiology of many diseases including proliferative retinopathy, age-related macular degeneration and cancer. A mouse model of microvascular angiogenesis would be very valuable and enable access to a wide range of genetically manipulated tissues that closely approximate small blood vessel growth in vivo. Vascular endothelial cells cultured in vitro are widely used, however, isolating pure vascular murine endothelial cells is technically challenging. A microvascular mouse explant model that is robust, quantitative and can be reproduced without difficulty would overcome these limitations. Here we characterized and optimized for reproducibility an organotypic microvascular angiogenesis mouse and rat model from the choroid, a microvascular bed in the posterior of eye. The choroidal tissues from C57BL/6J and 129S6/SvEvTac mice and Sprague Dawley rats were isolated and incubated in Matrigel. Vascular sprouting was comparable between choroid samples obtained from different animals of the same genetic background. The sprouting area, normalized to controls, was highly reproducible between independent experiments. We developed a semi-automated macro in ImageJ software to allow for more efficient quantification of sprouting area. Isolated choroid explants responded to manipulation of the external environment while maintaining the local interactions of endothelial cells with neighboring cells, including pericytes and macrophages as evidenced by immunohistochemistry and fluorescence-activated cell sorting (FACS) analysis. This reproducible ex vivo angiogenesis assay can be used to evaluate angiogenic potential of pharmacologic compounds on microvessels and can take advantage of genetically manipulated mouse tissue for microvascular disease research

Retinal lipid and glucose metabolism dictates angiogenesis through the lipid sensor Ffar1

Tissues with high metabolic rates often use lipids, as well as glucose, for energy, conferring a survival advantage during feast and famine1. Current dogma suggests that high-energy–consuming photoreceptors depend on glucose2, 3. Here we show that the retina also uses fatty acid β-oxidation for energy. Moreover, we identify a lipid sensor, free fatty acid receptor 1 (Ffar1), that curbs glucose uptake when fatty acids are available. Very-low-density lipoprotein receptor (Vldlr), which is present in photoreceptors4 and is expressed in other tissues with a high metabolic rate, facilitates the uptake of triglyceride-derived fatty acid5, 6. In the retinas of Vldlr−/− mice with low fatty acid uptake6 but high circulating lipid levels, we found that Ffar1 suppresses expression of the glucose transporter Glut1. Impaired glucose entry into photoreceptors results in a dual (lipid and glucose) fuel shortage and a reduction in the levels of the Krebs cycle intermediate α-ketoglutarate (α-KG). Low α-KG levels promotes stabilization of hypoxia-induced factor 1a (Hif1a) and secretion of vascular endothelial growth factor A (Vegfa) by starved Vldlr−/− photoreceptors, leading to neovascularization. The aberrant vessels in the Vldlr−/− retinas, which invade normally avascular photoreceptors, are reminiscent of the vascular defects in retinal angiomatous proliferation, a subset of neovascular age-related macular degeneration (AMD)7, which is associated with high vitreous VEGFA levels in humans. Dysregulated lipid and glucose photoreceptor energy metabolism may therefore be a driving force in macular telangiectasia, neovascular AMD and other retinal diseases

Unraveling synthesis of the cryptococcal cell wall and capsule

Fungal pathogens cause devastating infections in millions of individuals each year, representing a huge but underappreciated burden on human health. One of these, the opportunistic fungus Cryptococcus neoformans, kills hundreds of thousands of patients annually, disproportionately affecting people in resource-limited areas. This yeast is distinguished from other pathogenic fungi by a polysaccharide capsule that is displayed on the cell surface. The capsule consists of two complex polysaccharide polymers: a mannan substituted with xylose and glucuronic acid, and a galactan with galactomannan side chains that bear variable amounts of glucuronic acid and xylose. The cell wall, with which the capsule is associated, is a matrix of alpha and beta glucans, chitin, chitosan, and mannoproteins. In this review, we focus on synthesis of the wall and capsule, both of which are critical for the ability of this microbe to cause disease and are distinct from structures found in either model yeasts or the mammals afflicted by this infection. Significant research effort over the last few decades has been applied to defining the synthetic machinery of these two structures, including nucleotide sugar metabolism and transport, glycosyltransferase activities, polysaccharide export, and assembly and association of structural elements. Discoveries in this area have elucidated fundamental biology and may lead to novel targets for antifungal therapy. In this review, we summarize the progress made in this challenging and fascinating area, and outline future research questions

Unraveling synthesis of the cryptococcal cell wall and capsule

Fungal pathogens cause devastating infections in millions of individuals each year, representing a huge but underappreciated burden on human health. One of these, the opportunistic fungus Cryptococcus neoformans, kills hundreds of thousands of patients annually, disproportionately affecting people in resource-limited areas. This yeast is distinguished from other pathogenic fungi by a polysaccharide capsule that is displayed on the cell surface. The capsule consists of two complex polysaccharide polymers: a mannan substituted with xylose and glucuronic acid, and a galactan with galactomannan side chains that bear variable amounts of glucuronic acid and xylose. The cell wall, with which the capsule is associated, is a matrix of alpha and beta glucans, chitin, chitosan, and mannoproteins. In this review, we focus on synthesis of the wall and capsule, both of which are critical for the ability of this microbe to cause disease and are distinct from structures found in either model yeasts or the mammals afflicted by this infection. Significant research effort over the last few decades has been applied to defining the synthetic machinery of these two structures, including nucleotide sugar metabolism and transport, glycosyltransferase activities, polysaccharide export, and assembly and association of structural elements. Discoveries in this area have elucidated fundamental biology and may lead to novel targets for antifungal therapy. In this review, we summarize the progress made in this challenging and fascinating area, and outline future research questions

Representativeness of obstetric patients who participate in perinatal depression research: findings from the Women\u27s Mental Health and Infants Program (WMHIP) integrated dataset

The aims of this study were to evaluate the feasibility of integrating archival datasets from depression projects involving pregnant women recruited from obstetric clinics and then assess the representativeness of the integrated dataset. Datasets from six studies were standardized and integrated. Chi-square, t-, and Wilcoxon rank-sum tests were used to compare characteristics between women who completed a depression screening questionnaire (DSQ) and were (1) eligible and ineligible for research participation and (2) eligible women who accepted and declined participation. The integrated dataset comprises 9,112 pregnant women, of whom 71.0 % (n = 6,472) were ineligible for participation because their DSQ scores indicated no-to-minimal depressive symptoms (NDS). Among the 23.9 % (2,176) of women identified as eligible, in part, because their DSQ scores indicated elevated levels of depressive symptoms (EDS), 29.6 % (644) of women participated (P-EDS) and 47.6 % (1,036) of women did not participate (D-EDS). While the NDS and EDS groups were significantly different on almost all variables, the P-EDS and D-EDS groups were significantly different on only a few variables. Compared to the D-EDS group, the P-EDS group was earlier in pregnancy and, on the Edinburgh Postnatal Depression Screen, was more likely to endorse impaired “ability to laugh” and “enjoy oneself”, and endorse at greater severity “ability to laugh.” It is a reasonable and feasible strategy to integrate thematically similar datasets to increase statistical power. Additionally, typical recruitment strategies for minimal risk perinatal depression research at obstetric clinics, during routine prenatal care visits, appear to produce an externally valid study cohort

Positive margin rates for colorectal cancer vary significantly by hospital in Michigan: Can we achieve a 0 % positive margin rate?

Background: High quality surgical care for colorectal cancer (CRC) includes obtaining a negative surgical margin. The Michigan Surgical Quality Collaborative (MSQC) is a statewide consortium of hospitals dedicated to quality improvement; a subset of MSQC hospitals abstract quality of care measures for CRC surgery, including positive margin rate. The purpose of this study was to determine whether positive margin rates vary significantly by hospital, and whether positive margin rates should be a target for quality improvement. Methods: We performed a retrospective cohort study of patients who underwent CRC resection from 2016 to 2020. The primary outcome was the presence of a positive margin. Univariate and multivariable analyses were performed to test the association of positive margins with patient, hospital, and tumor characteristics. Results: The cohort consisted of 4211 patients from 42 hospitals (85 % colon cancer and 15 % rectal cancer). The crude positive margin rate was 6.15 % (95 % CI 4.6–7.4 %); this ranged from 0 % to 22 % at individual hospitals. In multivariable analysis, factors independently associated with positive margins included male sex, underweight BMI, metastatic cancer, rectal cancer (vs. colon), T4 T-stage, N1c/N2 N-stage, and open surgical approach. After adjusting for these factors, there remained significant variation by hospital, with 8 hospitals being statistically-significant outliers. Conclusions: Positive margins rates for CRC vary by hospital in Michigan, even after rigorous adjustment for case-mix. Furthermore, several hospitals achieved near-zero positive margin rates, suggesting opportunities for quality improvement through the identification of best practices among CRC surgery centers

A Social Media-Based Public Health Campaign to Reduce Indoor Tanning in High-Risk Populations.

INTRODUCTION: Indoor tanning beds cause more than 450,000 new skin cancers each year, yet their use remains common, with a global indoor tanning prevalence of 10.4%. Social media provides an opportunity for cost-effective, targeted public health messaging. We sought to direct Instagram users at high risk of indoor tanning to accurate health information about the risks of indoor tanning and to reduce indoor tanning bed use. METHODS: We disseminated a public health campaign on Instagram on April 6-27, 2022 with 34 video and still-image advertisements. We had 2 target audiences at high risk of indoor tanning: women aged 18-30 years in Kentucky, Nebraska, Ohio, or Tennessee interested in indoor tanning and men aged 18-45 years in California interested in indoor tanning. To evaluate the impact of the campaign, we tracked online metrics, including website visits, and conducted an interrupted time-series analysis of foot traffic data in our target states for all tanning salons documented on SafeGraph from January 1, 2018 to 3 months after the campaign. RESULTS: Our indoor tanning health information advertisements appeared on Instagram feeds 9.1 million times, reaching 1.06 million individuals. We received 7,004 views of our indoor tanning health information landing page (Average Time on Page of 56 seconds). We did not identify a significant impact on foot traffic data on tanning salons. CONCLUSIONS: We show the successful use of social media advertising to direct high-risk groups to online health information about indoor tanning. Future research quantifying tanning visits before and after indoor tanning interventions is needed to guide future public health efforts