Clustering phenotype populations by genome-wide RNAi and multiparametric imaging

How to predict gene function from phenotypic cues is a longstanding question in biology.Using quantitative multiparametric imaging, RNAi-mediated cell phenotypes were measured on a genome-wide scale.On the basis of phenotypic ‘neighbourhoods', we identified previously uncharacterized human genes as mediators of the DNA damage response pathway and the maintenance of genomic integrity.The phenotypic map is provided as an online resource at http://www.cellmorph.org for discovering further functional relationships for a broad spectrum of biological modul

Protease- and cell type–specific activation of protease-activated receptor 2 in cutaneous inflammation

Background: Protease-activated receptor 2 (PAR2) signaling controls skin barrier function and inflammation, but the roles of immune cells and PAR2-activating pro teases in cutaneous diseases are poorly understood. Objective: To dissect PAR2 signaling contributions to skin inflammation with new ge netic and pharmacological tools. Methods/Results: We found markedly increased numbers of PAR2+ infiltrating my eloid cells in skin lesions of allergic contact dermatitis (ACD) patients and in the skin of contact hypersensitivity (CHS) in mice, a murine ACD model for T cell–mediated allergic skin inflammation. Cell type–specific deletion of PAR2 in myeloid immune cells as well as mutation-induced complete PAR2 cleavage insensitivity significantly re duced skin inflammation and hapten-specific Tc1/Th1 cell response. Pharmacological approaches identified individual proteases involved in PAR2 cleavage and demon strated a pivotal role of tissue factor (TF) and coagulation factor Xa (FXa) as upstream activators of PAR2 in both the induction and effector phase of CHS. PAR2 mutant mouse strains with differential cleavage sensitivity for FXa versus skin epithelial cell–expressed proteases furthermore uncovered a time-dependent regulation of CHS development with an important function of FXa-induced PAR2 activation during the late phase of skin inflammation. Conclusions: Myeloid cells and the TF–FXa–PAR2 axis are key mediators and poten tial therapeutic targets in inflammatory skin disease

Thymic stromal lymphopoietin fosters human breast tumor growth by promoting type 2 inflammation

TSLP released from human breast cancer cells promotes OX40L expression on DCs, and these OX40L-expressing DCs drive development of inflammatory Th2 cells which promote breast tumor development

Slc7a11/xCT mediated ferroptosis repression in dermal fibroblasts promotes cutaneous fibrosis

Here we demonstrate that the Slc7a11/xCT pathway, which represses iron-dependent cell death (ferroptosis) by preventing reactive oxygen species-mediated lipid peroxidation, is upregulated in dermal fibroblasts in SSc patients and in a mouse model of oxidative stress-induced skin fibrosis. We observe that deficiency or inhibition of Slc7a11 prevents fibrosis and collagen accumulation. We further show that SSc dermal fibroblasts counteract ferroptosis by reducing the intracellular Fe2+ pool through enhanced ferritin storage thereby reducing lipid ROS sensitivity and lipid peroxidation. In line, SSc patients had low plasma iron levels and transferrin saturation rates and their fibroblasts contained less labile Fe2+ and showed less lipid peroxidation compared to healthy fibroblasts.</p

Delayed mortality among solid organ transplant recipients hospitalized for COVID-19.

INTRODUCTION: Most studies of solid organ transplant (SOT) recipients with COVID-19 focus on outcomes within one month of illness onset. Delayed mortality in SOT recipients hospitalized for COVID-19 has not been fully examined. METHODS: We used data from a multicenter registry to calculate mortality by 90 days following initial SARS-CoV-2 detection in SOT recipients hospitalized for COVID-19 and developed multivariable Cox proportional-hazards models to compare risk factors for death by days 28 and 90. RESULTS: Vital status at day 90 was available for 936 of 1117 (84%) SOT recipients hospitalized for COVID-19: 190 of 936 (20%) died by 28 days and an additional 56 of 246 deaths (23%) occurred between days 29 and 90. Factors associated with mortality by day 90 included: age \u3e 65 years [aHR 1.8 (1.3-2.4), p = CONCLUSIONS: In SOT recipients hospitalized for COVID-19, \u3e20% of deaths occurred between 28 and 90 days following SARS-CoV-2 diagnosis. Future investigations should consider extending follow-up duration to 90 days for more complete mortality assessment

Changing trends in mortality among solid organ transplant recipients hospitalized for COVID-19 during the course of the pandemic.

Mortality among patients hospitalized for COVID-19 has declined over the course of the pandemic. Mortality trends specifically in solid organ transplant recipients (SOTR) are unknown. Using data from a multicenter registry of SOTR hospitalized for COVID-19, we compared 28-day mortality between early 2020 (March 1, 2020-June 19, 2020) and late 2020 (June 20, 2020-December 31, 2020). Multivariable logistic regression was used to assess comorbidity-adjusted mortality. Time period of diagnosis was available for 1435/1616 (88.8%) SOTR and 971/1435 (67.7%) were hospitalized: 571/753 (75.8%) in early 2020 and 402/682 (58.9%) in late 2020 (p \u3c .001). Crude 28-day mortality decreased between the early and late periods (112/571 [19.6%] vs. 55/402 [13.7%]) and remained lower in the late period even after adjusting for baseline comorbidities (aOR 0.67, 95% CI 0.46-0.98, p = .016). Between the early and late periods, the use of corticosteroids (≥6 mg dexamethasone/day) and remdesivir increased (62/571 [10.9%] vs. 243/402 [61.5%], p \u3c .001 and 50/571 [8.8%] vs. 213/402 [52.2%], p \u3c .001, respectively), and the use of hydroxychloroquine and IL-6/IL-6 receptor inhibitor decreased (329/571 [60.0%] vs. 4/492 [1.0%], p \u3c .001 and 73/571 [12.8%] vs. 5/402 [1.2%], p \u3c .001, respectively). Mortality among SOTR hospitalized for COVID-19 declined between early and late 2020, consistent with trends reported in the general population. The mechanism(s) underlying improved survival require further study

COVID‐19 in hospitalized lung and non‐lung solid organ transplant recipients: A comparative analysis from a multicenter study

Lung transplant recipients (LTR) with coronavirus disease 2019 (COVID-19) may have higher mortality than non-lung solid organ transplant recipients (SOTR), but direct comparisons are limited. Risk factors for mortality specifically in LTR have not been explored. We performed a multicenter cohort study of adult SOTR with COVID-19 to compare mortality by 28&nbsp;days between hospitalized LTR and non-lung SOTR. Multivariable logistic regression models were used to assess comorbidity-adjusted mortality among LTR vs. non-lung SOTR and to determine risk factors for death in LTR. Of 1,616 SOTR with COVID-19, 1,081 (66%) were hospitalized including 120/159 (75%) LTR and 961/1457 (66%) non-lung SOTR (p&nbsp;=&nbsp;.02). Mortality was higher among LTR compared to non-lung SOTR (24% vs. 16%, respectively, p&nbsp;=&nbsp;.032), and lung transplant was independently associated with death after adjusting for age and comorbidities (aOR 1.7, 95% CI 1.0-2.6, p&nbsp;=&nbsp;.04). Among LTR, chronic lung allograft dysfunction (aOR 3.3, 95% CI 1.0-11.3, p&nbsp;=&nbsp;.05) was the only independent risk factor for mortality and age &gt;65 years, heart failure and obesity were not independently associated with death. Among SOTR hospitalized for COVID-19, LTR had higher mortality than non-lung SOTR. In LTR, chronic allograft dysfunction was independently associated with mortality

Covid-19 in hospitalized lung and non-lung solid organ transplant recipients: a comparative analysis from a multicenter study.

Lung transplant recipients (LTR) with Covid-19 may have higher mortality than non-lung solid organ transplant recipients (SOTR), but direct comparisons are limited. Risk factors for mortality specifically in LTR have not been explored. We performed a multicenter cohort study of adult SOTR with Covid-19 to compare mortality by 28-days between hospitalized LTR and non-lung SOTR. Multivariable logistic regression models were used to assess comorbidity-adjusted mortality among LTR vs. non-lung SOTR and to determine risk factors for death in LTR. Of 1,616 SOTR with Covid-19, 1,051 (65%) were hospitalized including 117/159 (74%) LTR and 934/1457 (64%) non-lung SOTR (p=0.02). Mortality was higher among LTR compared to non-lung SOTR (24% vs. 16%, respectively, p=0.035) and lung transplant was independently associated with death after adjusting for age and comorbidities (aOR 1.7, 95% CI 1.0-2.6, p=0.05). Among LTR, independent risk factors for mortality included single lung transplant (aOR 2.8, 95% CI 1.0-7.7, p=0.04) and chronic lung allograft dysfunction (aOR 3.6, 95% CI 1.0-12.4, p=0.05), but not age \u3e65 years, heart failure, or obesity. Among SOTR hospitalized for Covid-19, LTR had higher mortality than non-lung SOTR. In LTR, single lung transplant and chronic allograft dysfunction were independently associated with mortality