BACKGROUND. NAFLD affects 25-30% of the US and European populations and is associated with insulin resistance (IR), T2D, increased cardiovascular risk and is defined by hepatic triglyceride content (HTG) > 5.56%. However, it is unknown whether HTG content less than 5.56% is associated with cardiometabolic risk factors and whether there are ethnic [Asian Indian (AI) vs. non-Asian Indian (non-AI)] and/or gender differences in these parameters in lean individuals. METHODS. We prospectively recruited 2,331 individuals and measured HTG, using 1H MRS, and plasma concentrations of triglycerides, total cholesterol, LDL cholesterol, HDL cholesterol, and uric acid. Insulin sensitivity was assessed using HOMA-IR and the Matsuda Insulin Sensitivity Index (ISI). RESULTS. The 95th percentile for HTG in lean non-AI individuals was 1.85%. Plasma insulin, triglycerides, total cholesterol, LDL cholesterol and uric acid concentrations were increased and HDL decreased in individuals with HTG content > 1.85% and ≤ 5.56% compared to those individuals with HTG content ≤ 1.85% and was associated with increased IR. Mean HTG was lower in lean non-AI women compared to lean non-AI men, whereas lean AI men and women had a 40-100% increase in HTG when compared to non-AI men and women which was associated with increased cardiometabolic risk factors. CONCLUSIONS. We found that the 95th percentile of HTG in lean non-AI individuals was 1.85% and that HTG concentrations above this threshold were associated with IR and cardiovascular risk factors. Premenopausal women are protected from these changes whereas young lean AI men and women manifest increased HTG content and associated cardiometabolic risk factors. FUNDING. Supported by grants from the United States Department of Health and Human Resources (NIH/NIDDK): R01 DK113984, P30 DK45735, U24 DK59635 and UL1 RR024139 and the Novo Nordisk Foundation (NNF18CC0034900).
Kitt Falk Petersen, Sylvie Dufour, Fangyong Li, Douglas L. Rothman, Gerald I. Shulman
Kawasaki disease (KD) is the leading cause of non-congenital heart disease in children. Studies in mice and humans propound the NLRP3-IL-1β pathway as the principal driver of KD pathophysiology. Endoplasmic reticulum (ER) stress can activate the NLRP3 inflammasome, but the potential implication of ER stress in KD pathophysiology has not been investigated. We used human patient data and the Lactobacillus casei cell wall extract (LCWE) murine model of KD vasculitis to characterize the impact of ER stress on the development of cardiovascular lesions. KD patient transcriptomics and single-cell RNA sequencing of the abdominal aorta from LCWE-injected mice revealed changes in the expression of ER stress genes. Alleviating ER stress genetically, by conditional deletion of Inositol Requiring Enzyme-1 (IRE1) in myeloid cells, or pharmacologically, by inhibition of IRE1 endoribonuclease (RNase) activity, led to significant reduction of LCWE-induced cardiovascular lesion formation as well as reduced caspase-1 activity and IL-1β secretion. These results demonstrate the causal relationship of ER stress to KD pathogenesis, and highlight IRE1 RNase activity as a potential new therapeutic target.
Stefanie Marek-Iannucci, Asli D. Yildirim, Syed M. Hamid, Asli B. Ozdemir, Angela C. Gomez, Begüm Kocatürk, Rebecca A. Porritt, Michael C. Fishbein, Takao Iwawaki, Magali Noval Rivas, Ebru Erbay, Moshe Arditi
Sporozoite-based approaches currently represent the most effective vaccine strategies for induction of sterile protection against Plasmodium falciparum (Pf) malaria. Clinical development of sub-unit vaccines is almost exclusively centered around the Circum-sporozoite Protein (CSP) an abundantly expressed protein on the sporozoite membrane. Anti-CSP antibodies are able to block sporozoite invasion and development in human hepatocytes and subsequently prevent clinical malaria. Here we investigated whether sporozoite-induced human antibodies with specificities different from CSP can reduce Pf-liver stage development. IgG preparations were obtained from 12 volunteers inoculated with a protective immunization regime of whole-sporozoites under chloroquine prophylaxis. These IgGs were depleted for CSP-specificity by affinity chromatography. Recovered non-CSP antibodies were tested for sporozoite membrane binding and for functional inhibition of sporozoite invasion of a human hepatoma cell line and hepatocytes both in vitro and in vivo. Post-immunization IgGs depleted for CSP-specificity of 9 out of 12 donors recognized sporozoite surface antigens. Samples from 5 out of 12 donors functionally reduced parasite-liver cell invasion or development using the hepatoma cell line HC-04 and FRG-huHep mice containing human liver cells. The combined data provide clear evidence that non-CSP proteins as yet undefined do represent antibody targets for functional immunity against Plasmodium falciparum parasites responsible for malaria.
Amanda Fabra-García, Annie S.P. Yang, Marije C. Behet, Xi Zen Yap, Youri van Waardenburg, Swarnendu Kaviraj, Kjerstin Lanke, Geert-Jan van Gemert, Matthijs M. Jore, Teun Bousema, Robert W. Sauerwein
Ca2+ is critical for cardiac electrical conduction and contractility, and aberrant Ca2+ homeostasis causes arrhythmia and heart failure. Chromatin remodeling modulates gene expression involved in cardiac sarcomere assembly and postnatal heart function. However, the chromatin remodeling-regulatory cardiac Ca2+ homeostasis is unknown. Here, we found that Znhit1, a core subunit of the SRCAP remodeling complex, was essential for heart function. Deletion of Znhit1 in postnatal heart of mice resulted in arrhythmia, idiopathic vacuolar cardiomyopathy, rapid heart failure and premature sudden death. In addition, the level of Casq1, a sarcoplasmic reticulum (SR) Ca2+ regulatory protein, was massively elevated while SERCA2a showed reduced protein level. Mechanistically, the Znhit1 modulated the expression of Casq1 and SERCA2a through depositing H2A.Z at their promoters. Deletion of Casq1 could substantially alleviate the vacuolar formation in Znhit1 cKO mice. These findings have demonstrated that Znhit1 is required for post-natal heart function and maintains cardiac Ca2+ homeostasis, and accumulation of Casq1 might be a causative factor for vacuolar cardiomyopathy.
Yingchao Shi, Wenli Fan, Mingjie Xu, Xinhua Lin, Wukui Zhao, Zhongzhou Yang
Cilia, microtubule-based organelles that project from the apical luminal surface of endothelial cells (ECs), are widely regarded as a low flow-sensors. Previous reports suggest that upon high shear stress, cilia on the EC surface are lost, and more recent evidence suggests that deciliation - the physical removal of cilia from the cell surface - is a predominant mechanism for cilia loss in mammalian cells. Thus, we hypothesized that EC deciliation facilitated by changes in shear stress will manifest in increased abundance of cilia-related proteins in circulation. To test this hypothesis, we performed shear stress experiments that mimicked flow conditions from low to high shear stress in human primary cells and a zebrafish model system. In the primary cells, we showed that upon shear stress induction, indeed, ciliary fragments were observed in the effluent in vitro and effluents contained ciliary proteins normally expressed in both endothelial and epithelial cells. In zebrafish, upon shear stress induction, fewer ciliary-expressing ECs were observed. To test the translational relevance of these findings, we investigated our hypothesis using patient blood samples from sickle cell disease and found that plasma levels of ciliary proteins were elevated compared to healthy controls. Further, sickled red blood cells demonstrated high levels of ciliary protein (Arl13b) on their surface post-adhesion to brain ECs. Brain ECs post interaction with sickle RBCs show high reactive oxygen species (ROS) levels. Attenuating ROS levels in brain ECs decreases cilia protein levels on RBCs and rescues ciliary protein levels in brain ECs. Collectively, these data suggest that cilia and ciliary proteins in circulation are detectable under various altered flow conditions, which could serve as a surrogate biomarker of the damaged endothelium.
Ankan Gupta, Karthikeyan Thirugnanam, Madhan Thamilarasan, Ashraf M. Mohieldin, Hadeel T. Zedan, Shubhangi Prabhudesai, Meghan R. Griffin, Andrew D. Spearman, Amy Pan, Sean P. Palecek, Huseyin C. Yalcin, Surya M. Nauli, Kevin R. Rarick, Rahima Zennadi, Ramani Ramchandran
Mucosal healing is a key treatment goal for inflammatory bowel disease, and adequate epithelial regeneration is required for an intact gut epithelium. However, the underlying mechanism is unclear. Long non-coding RNAs (lncRNAs) have been reported to be involved in the development of inflammatory bowel disease. Here, we report that a lncRNA named Gm31629, decreases in intestinal epithelial cells in response to inflammatory stimulation. Gm31629 deficiency leads to exacerbated intestinal inflammation and delayed epithelial regeneration in dextran sulfate sodium (DSS) -induced colitis model. Mechanistically, Gm31629 promotes E2F pathways and cell proliferation by stabilizing Y-box protein 1 (YB-1), thus facilitating epithelial regeneration. Genetic overexpression of Gm31629 protects against DSS-induced colitis in vivo. Theaflavin 3-gallate, a natural compound mimicking Gm31629, alleviates DSS-induced epithelial inflammation and mucosal damage. These results demonstrate an essential role of lncRNA Gm31629 in linking intestinal inflammation and epithelial cell proliferation, providing a potential therapeutic approach to inflammatory bowel disease.
Xu Feng, Ye Xiao, Jian He, Mi Yang, Qi Guo, Tian Su, Yan Huang, Jun Yi, Chang-Jun Li, Xiang-Hang Luo, Xiao-Wei Liu, Hai-Yan Zhou
Severe acute lung injury has few treatment options and a high mortality rate. Upon injury, neutrophils infiltrate the lungs and form neutrophil extracellular traps (NETs), damaging the lungs and driving an exacerbated immune response. Unfortunately, no drug preventing NET formation has completed clinical development. Here, we report that disulfiram —an FDA-approved drug for alcohol use disorder— dramatically reduced NETs, increased survival, improved blood oxygenation, and reduced lung edema in a transfusion-related acute lung injury (TRALI) mouse model. We then tested whether disulfiram could confer protection in the context of SARS-CoV-2 infection, as NETs are elevated in patients with severe COVID-19. In SARS-CoV-2-infected golden hamsters, disulfiram reduced NETs and perivascular fibrosis in the lungs, and downregulated innate immune and complement/coagulation pathways, suggesting that it could be beneficial for COVID-19 patients. In conclusion, an existing FDA-approved drug can block NET formation and improve disease course in two rodent models of lung injury for which treatment options are limited.
Jose M. Adrover, Lucia Carrau, Juliane Daßler-Plenker, Yaron Bram, Vasuretha Chandar, Sean Houghton, David Redmond, Joseph R. Merrill, Margaret Shevik, Benjamin R. tenOever, Scott K. Lyons, Robert E. Schwartz, Mikala Egeblad
Recovery from pneumococcal pneumonia remodels the pool of alveolar macrophages so that they exhibit new surface marker profiles, transcriptomes, metabolomes, and responses to infection. Mechanisms mediating alveolar macrophage phenotypes after pneumococcal pneumonia have not been delineated. IFNγ and its receptor on alveolar macrophages were essential for aspects but not all of the remodeled alveolar macrophage phenotype. IFNγ was produced by CD4+ T cells plus other cells, and CD4+ cell depletion did not prevent alveolar macrophage remodeling. In mice infected or recovering from pneumococcus, monocytes were recruited to the lungs and the monocyte-derived macrophages developed characteristics of alveolar macrophages. CCR2 mediated the early monocyte recruitment but was not essential to development of the remodeled alveolar macrophage phenotype. Lineage tracing demonstrated that recovery from pneumococcal pneumonias converted the pool of alveolar macrophages from being primarily of embryonic origin to being primarily of adult hematopoietic stem cell origin. Alveolar macrophages of either origin demonstrated similar remodeled phenotypes, suggesting that ontogeny did not dictate phenotype. Altogether, our data reveal that the remodeled alveolar macrophage phenotype in lungs recovered from pneumococcal pneumonia results from a combination of new recruitment plus training of both the original cells and the new recruits.
Emad I. Arafa, Anukul T. Shenoy, Kimberly A. Barker, Neelou S. Etesami, Ian M.C. Martin, Carolina Lyon De Ana, Elim Na, Christine V. Odom, Wesley N. Goltry, Filiz T. Korkmaz, Alicia K. Wooten, Anna C. Belkina, Antoine Guillon, E. Camilla Forsberg, Matthew R. Jones, Lee J. Quinton, Joseph P. Mizgerd
BACKGROUND. Pathophysiology of type 1 diabetes (T1D) is illustrated by pancreatic islet infiltration of inflammatory lymphocytes, including CD8+ T-cells; however, the molecular factors mediating their recruitment remain unknown. We hypothesized that single-cell RNA-sequencing (scRNA-Seq) analysis of immune cell populations isolated from islets of non-obese diabetic (NOD) mice captured gene expression dynamics providing critical insight into autoimmune diabetes pathogenesis. METHODS. Pancreatic sections from human donors were investigated, including T1D subjects, auto-antibody-positive (aAb+), and non-diabetic controls. Immunohistochemistry was performed to assess islet hormones, and both novel and canonical immune-cell markers that were identified from state-of-the-art workflows after reanalyzing murine scRNA-seq datasets. RESULTS. Computational workflows identified Cadm1-mediated binding among the most significant intercellular interactions among all cell clusters as well as Cadm1 enrichment in macrophages and dendritic cells from pancreata of NOD mice. Immunostaining of human pancreata revealed an increased number of CADM1+GCG+ cells adjacent to CD8+ T-cells in sections from T1D and aAb+ donors compared to non-diabetic subjects. Numbers of CADM1+CD68+ peri-islet myeloid cells adjacent to CD8+ T-cells were also increased in pancreatic sections from both T1D and aAb+ donors compared to non-diabetic subjects. CONCLUSION. Increased detection of CADM1+ cells adjacent to CD8+ T-cells in pancreatic sections of T1D and aAb+ human subjects validated workflows, and indicates CADM1-mediated intercellular contact may facilitate islet infiltration of cytotoxic T lymphocytes and serve as a potential therapeutic target for preventing T1D pathogenesis. FUNDING. The Johns Hopkins All Children’s Foundation IRG Program, NSFC (82071326) and DFG (431549029–SFB 1451, EXC 2030–390661388, and 411422114-GRK 2550).
Chandan Sona, Yu-Te Yeh, Andreas Patsalos, Laszlo Halasz, Xin Yan, Natalia L. Kononenko, Laszlo Nagy, Matthew N. Poy
BACKGROUND. Paclitaxel chemotherapy frequently induces dose-limiting sensory axonal polyneuropathy. As sensory symptoms are challenging to assess objectively in clinical routine, an easily accessible biomarker for chemotherapy-induced polyneuropathy (CIPN) holds the potential to improve early diagnosis. Here, we describe neurofilament light chain (NFL), a marker for neuroaxonal damage, as translational surrogate marker for CIPN. METHODS. NFL concentrations were measured in an in vitro model of CIPN, exposing induced pluripotent stem cell-derived sensory neurons (iPSC-DSN) to paclitaxel. Breast and ovarian cancer patients undergoing paclitaxel chemotherapy, breast cancer control patients without chemotherapy and healthy controls were recruited in a cohort study and examined before chemotherapy (V1) and after 28 weeks (V2, after chemotherapy). CIPN was assessed by the validated Total Neuropathy Score reduced, which combines patient-reported symptoms with data from clinical examinations. Serum NFL (NFLs) concentrations were measured at both visits with single molecule array technology (SIMOA). RESULTS. NFL is released from iPSC-DSN upon paclitaxel incubation in a dose- and time-dependent manner and inversely correlates with iPSC-DSN viability. NFLs strongly increased in paclitaxel-treated patients with CIPN, but not in chemotherapy patients without CIPN or controls, resulting in an 86 % sensitivity and 87 % specificity. A NFLs increase of +36 pg/ml from baseline was associated with a predicted CIPN probability of >0.5. CONCLUSION. NFLs correlates with CIPN development and severity, which may guide neurotoxic chemotherapy in the future. TRIAL REGISTRATION. NCT02753036 FUNDING. DFG (EXC 257 NeuroCure), BMBF (01 EO 0801), AnimalFreeResearch Organization, EU Horizon 2020 Innovative Medicines Initiative 2 Joint Undertaking (TransBioLine, 821283)
Petra Huehnchen, Christian Schinke, Nikola Bangemann, Adam D. Dordevic, Johannes Kern, Smilla K. Maierhof, Lois Hew, Luca Nolte, Peter Körtvelyessy, Jens C. Göpfert, Klemens Ruprecht, Christopher J. Somps, Jens-Uwe Blohmer, Jalid Sehouli, Matthias Endres, Wolfgang Boehmerle
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