Ramzan et al. report that changes in the carboxypeptidase D gene cause congenital hearing loss by harming inner ear cells and suggest a potential therapeutic strategy targeting the nitric oxide pathway. The cover art is a modified version of confocal micrographs showing immunolabeled neuronal membranes, cap rods, scolopale rods, and actin bundles within the cilium in Johnston’s organ, a component of the auditory system required for sensing gravity, wind flow, and near-field sound. Image credit: Natalie Ortiz-Vega, Memoona Ramzan, Thomas J. Diefenbach, and Chong Li.
BACKGROUND. Critically ill patients with acute respiratory distress syndrome (ARDS) and sepsis exhibit distinct inflammatory phenotypes with divergent clinical outcomes, but the underlying molecular mechanisms remain poorly understood. These phenotypes, derived from clinical data and protein biomarkers, were associated with metabolic differences in a pilot study. METHODS. We performed integrative multi-omics analysis of blood samples from 160 ARDS patients in the ROSE trial, randomly selecting 80 patients from each latent class analysis-defined inflammatory phenotype (Hyperinflammatory and Hypoinflammatory) with phenotype probability >0.9. Untargeted plasma metabolomics and whole blood transcriptomics at Day 0 and Day 2 were analyzed using multi-modal factor analysis (MEFISTO). The primary outcome was 90-day mortality, with validation in an independent critically ill sepsis cohort (EARLI). RESULTS. Multi-omics integration revealed four molecular signatures associated with mortality: (1) enhanced innate immune activation coupled with increased glycolysis (associated with Hyperinflammatory phenotype), (2) hepatic dysfunction and immune dysfunction paired with impaired fatty acid beta-oxidation (associated with Hyperinflammatory phenotype), (3) interferon program suppression coupled with altered mitochondrial respiration (associated with Hyperinflammatory phenotype), and (4) redox impairment and cell proliferation pathways (not associated with inflammatory phenotype). These signatures persisted through Day 2 of trial enrollment. Within-phenotype analysis revealed distinct mortality-associated pathways in each group. All molecular signatures were validated in the independent EARLI cohort. CONCLUSIONS. Inflammatory phenotypes of ARDS reflect distinct underlying biological processes with both phenotype-specific and phenotype-independent pathways influencing patient outcomes, all characterized by mitochondrial dysfunction. These findings suggest potential therapeutic targets for precise treatment strategies in critical illness. FUNDING. This work is the result of NIH funding.
Narges Alipanah-Lechner, Lucile Neyton, Pratik Sinha, Carolyn Leroux, Kim Bardillon, Sidney A. Carrillo, Suzanna Chak, Olivia Chao, Taarini Hariharan, Carolyn Hendrickson, Kirsten Kangelaris, Charles R. Langelier, Deanna Lee, Chelsea Lin, Kathleen Liu, Liam Magee, Angelika Ringor, Aartik Sarma, Emma Schmiege, Natasha Spottiswoode, Kathryn Sullivan, Melanie F. Weingart, Andrew Willmore, Hanjing Zhuo, Angela J. Rogers, Kathleen A. Stringer, Michael A. Matthay, Carolyn S. Calfee
GATA6 is a master regulator of differentiation in the pancreas and its expression levels determine the two main molecular subtypes of pancreatic cancer. High GATA6 contributes to the “classical” pancreatic cancer subtype, which is associated with a higher degree of tumor differentiation and better disease prognosis. However, why GATA6 expression varies across pancreatic cancers and what regulate GATA6 expression remain elusive. Here we report that the oncogenic KRAS-activated ERK signaling suppresses GATA6 transcription in pancreatic cancers. GATA6 mRNA levels inversely correlated with KRAS/ERK activity in pancreatic tumors. A genome-wide CRISPR screen in a GATA6-EGFP reporter knockin cell line identified JUNB as the ERK-regulated transcriptional repressor for GATA6. Active ERK stabilizes JUNB protein while KRAS/ERK inhibition led to ubiquitin-independent proteasomal degradation of JUNB and increased transcription of GATA6. Up-regulation of GATA6 enhanced chemosensitivity of pancreatic cancer cells and KRAS/ERK inhibitors synergized with chemotherapy in a GATA6-dependent manner. Our study identifies how oncogenic KRAS/ERK signaling suppresses GATA6 to cause dedifferentiation in pancreatic cancer. Combining KRAS/ERK inhibitors with standard-of-care chemotherapies could be a promising therapeutic strategy for treating pancreatic cancers.
Zheng Zhong, Xinang Cao, Pei-Ju Liao, Raman Sethi, Jeffrey A. Klomp, Clint A. Stalnecker, Jinmiao Chen, Yue Wan, Channing J. Der, David M. Virshup
During vascular injury, platelets are essential for halting bleeding and recruiting neutrophils to prevent microbial invasion. However, in antibody-mediated autoimmune diseases occurring without vascular damage, neutrophils infiltrate tissues and contribute to pathology. Here, we investigated whether the dependence of neutrophils on platelets is conserved in the context of antibody-driven inflammation. Using human cells from individuals with rheumatoid arthritis and a microfluidic system mimicking physiological shear over IgG-containing immune complexes, we demonstrate that despite expressing Fc receptors, neutrophils require platelets to stably adhere to immune complexes under flow. Platelet FcγRIIA binding was critical for resisting shear stress, while neutrophils used FcγRIIA and FcγRIIIB for immune complex recognition. Platelet P-selectin binding to neutrophil PSGL-1 was essential for recruitment, whereas Mac-1 was dispensable. In a mouse model of autoantibody-mediated arthritis, intravital imaging confirmed that neutrophil recruitment critically relies on PSGL-1. Importantly, expression of FcyRIIA aggravated arthritis, and blockade of PSGL-1 in these mice, but not of Mac-1, abrogated both the platelet and neutrophil interactions and disease. These findings identify key molecular interactions in platelet–neutrophil cooperation and reveal that platelets are essential enablers of FcR-mediated neutrophil adhesion in antibody-driven inflammation.
Marie Bellio, Isabelle Allaeys, Etienne Doré, Myriam Vaillancourt, Tania Lévesque, Mélina Monteil, Nicolas Vallières, Philippe Desaulniers, Nicolas Bertrand, Valance A. Washington, Yotis Senis, Steve Lacroix, Paul Fortin, Clémence Belleannée, Eric Boilard
The role of CARD9 in the pathogenesis of various chronic fungal infections has been established; however, the precise mechanisms underlying the pathobiology of these infections remain unclear. We aimed to investigate the specific cellular mechanisms by which CARD9 deficiency contributes to the pathogenesis of chronic fungal infections. Using single-cell RNA sequencing (scRNA-seq), we analyzed the immune cell profiles in skin lesions from both murine and human samples. We focused on macrophage differentiation and signaling pathways influenced by CARD9 deficiency. We found that CARD9 deficiency promotes the differentiation of TREM2high macrophages following fungal stimulation, impairing their antifungal functions and inducing exhaustion-like T helper 1 (Th1) cells. Mechanistically, the NF-κB pathway activation was restricted in CARD9-deficient macrophages, leading to enhanced CREB activation, which in turn exerted a positive regulatory effect on Trem2 expression by activating C/EBPβ. Notably, targeting TREM2 enhanced the antifungal immune response in vivo and in vitro, thereby alleviating the severity of CARD9-deficient subcutaneous dematiaceous fungal infection. Our findings highlight the important role of CARD9 in regulating cutaneous antifungal immunity and identify potential targets for immunotherapy in chronic dematiaceous fungal infections.
Lu Zhang, Zhichun Tang, Yi Zhang, Wenjie Liu, Haitao Jiang, Li Yu, Kexin Lei, Yubo Ma, Yang-xin Fu, Ruoyu Li, Wenyan Wang, Fan Bai, Xiaowen Wang
Emerging evidence demonstrates that chronic stress alters immunological, neurochemical and endocrinological functions, thereby promoting tumor progression. However, the underlying metabolic mechanism of chronic stress in tumor progression is still elusive. Using multi-omics analysis, we found that aminopeptidase N (ANPEP) was upregulated in tumors with chronic restraint, associating with the reprogramming of amino acid metabolism. Functional assays revealed that ANPEP promoted liver cancer growth and metastasis. Knockdown of ANPEP blocked chronic stress-induced liver cancer progression. Chronic stress-induced glucocorticoids promoted nuclear receptor subfamily 3 group C member 1 (NR3C1) nuclear translocation to activate ANPEP transcription by directly binding to its promoter. Furthermore, ANPEP promotes glutathione synthesis, subsequently inhibiting reactive oxygen species (ROS)-induced ferroptosis. Mechanistically, ANPEP interacted with solute carrier family 3 member 2 (SLC3A2) to block membrane associated ring-CH-type finger 8-mediated (MARCH8-mediated) lysosome-dependent degradation of SLC3A2, promoting intracellular L-cystine transport, thereby increasing glutathione synthesis. The combination of ANPEP silencing and sorafenib treatment showed a synergistic effect in inhibiting liver cancer progression. Finally, clinical data and mouse models demonstrated that chronic stress drove liver tumor progression via ANPEP-regulated SLC3A2. These findings reveal unanticipated communication between chronic stress and metabolic reprogramming during liver cancer progression, providing potential therapeutic implications for liver cancer.
Yongkang Wu, Yankun Zhang, Xiaojia Shi, Mengting Wu, Min Sun, Ying Feng, Wenmeng Ma, Xiule Jiang, Dingqi Fei, Mingjian Zhao, Zhuanchang Wu, Chunyang Li, Xiaohong Liang, Lifen Gao, Chunhong Ma, Xuetian Yue
Therapies targeting the glucagon-like peptide 1 (GLP-1) receptor have revolutionized the treatment of obesity and diabetes. This series of reviews, curated by Dr. Dan Drucker, describes the latest research in this fast-moving in field, from our evolving understanding of the mechanism of GLP-1 receptor signaling to the medicines’ impact on inflammation and the consequences for heart, kidney, and brain health. The reviews also explore the impact of these medicines on conditions beyond their initial indications, including cancer and neurodegenerative disease risk.
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In this episode, Marie Jeansson explains how the paper's findings suggest that TIE2 activation via angiopoietin-2 (ANGPT2)-binding and TIE2-activating antibody warrants investigation as a therapy in human CKD...