Kuchroo, M;DiStasio, M;Song, E;Calapkulu, E;Zhang, L;Ige, M;Sheth, AH;Majdoubi, A;Menon, M;Tong, A;Godavarthi, A;Xing, Y;Gigante, S;Steach, H;Huang, J;Huguet, G;Narain, J;You, K;Mourgkos, G;Dhodapkar, RM;Hirn, MJ;Rieck, B;Wolf, G;Krishnaswamy, S;Hafler, BP;
PMID: 37147305 | DOI: 10.1038/s41467-023-37025-7
Due to commonalities in pathophysiology, age-related macular degeneration (AMD) represents a uniquely accessible model to investigate therapies for neurodegenerative diseases, leading us to examine whether pathways of disease progression are shared across neurodegenerative conditions. Here we use single-nucleus RNA sequencing to profile lesions from 11 postmortem human retinas with age-related macular degeneration and 6 control retinas with no history of retinal disease. We create a machine-learning pipeline based on recent advances in data geometry and topology and identify activated glial populations enriched in the early phase of disease. Examining single-cell data from Alzheimer's disease and progressive multiple sclerosis with our pipeline, we find a similar glial activation profile enriched in the early phase of these neurodegenerative diseases. In late-stage age-related macular degeneration, we identify a microglia-to-astrocyte signaling axis mediated by interleukin-1β which drives angiogenesis characteristic of disease pathogenesis. We validated this mechanism using in vitro and in vivo assays in mouse, identifying a possible new therapeutic target for AMD and possibly other neurodegenerative conditions. Thus, due to shared glial states, the retina provides a potential system for investigating therapeutic approaches in neurodegenerative diseases.
Rigoni R, Fontana E, Dobbs K, Marrella V, Taverniti V, Maina V, Facoetti A, D'Amico G, Al-Herz W, Cruz-Munoz ME, Schuetz C, Gennery AR, Garabedian EK, Giliani S, Draper D, Dbaibo G, Geha RS, Meyts I1, Tousseyn T, Neven B, Moshous D, Fischer A, Schulz A, Finocchi A, Kuhns DB, Fink DL, Lionakis MS, Swamydas M, Guglielmetti S, Alejo J, Myles IA, Pittaluga S, Notarangelo LD, Villa A, Cassani B
PMID: 32311393 | DOI: 10.1016/j.jaci.2020.04.005
BACKGROUND:
Severe early-onset erythroderma and gut inflammation, with massive tissue infiltration of oligoclonal activated T cells are the hallmark of Omenn Syndrome (OS).
OBJECTIVE:
The impact of altered gut homeostasis in the cutaneous manifestations of OS remains to be clarified.
METHODS:
We analyzed a cohort of 15 patients with OS and the Rag2R229Q mouse model. Homing phenotype of circulating lymphocytes were analyzed by flow cytometry. Inflammatory cytokines and chemokines were examined in the sera by ELISA and in skin biopsies by immunohistochemistry and in situ RNA hybridization. Experimental colitis was induced in mice by dextran sulfate sodium salt (DSS).
RESULTS:
We show that memory/activated T cells from OS patients and from the Rag2R229Q mouse model of OS abundantly express the skin homing receptors Cutaneous Lymphocyte Associated Antigen (CLA) and CCR4, associated with high levels of CCL17 and CCL22 chemokines. Serum levels of LPS are also elevated. A broad Th1/Th2/Th17 inflammatory signature is detected in the periphery and in the skin. Increased Tlr4 expression in the skin of Rag2R229Q mice is associated with enhanced cutaneous inflammation upon local and systemic administration of LPS. Likewise, boosting colitis in Rag2R229Q mice results in increased frequency of CCR4+ splenic T cells and worsening of skin inflammation, as indicated by epidermal thickening, enhanced epithelial cell activation and dermal infiltration by Th1 effector T cells.
CONCLUSIONS:
These results support the existence of an interplay between gut and skin that can sustain skin inflammation in O
Riedel, JH;Robben, L;Paust, HJ;Zhao, Y;Asada, N;Song, N;Peters, A;Kaffke, A;Borchers, AC;Tiegs, G;Seifert, L;Tomas, NM;Hoxha, E;Wenzel, UO;Huber, TB;Wiech, T;Turner, JE;Krebs, CF;Panzer, U;
PMID: 36355429 | DOI: 10.1172/jci.insight.160251
Glucocorticoids remain a cornerstone of therapeutic regimes for autoimmune and chronic inflammatory diseases, for example, in different forms of crescentic glomerulonephritis because of their rapid anti-inflammatory effects, low cost, and wide availability. Despite their routine use for decades, the underlying cellular mechanisms by which steroids exert their therapeutic effects need to be fully elucidated.Here, we demonstrate that high-dose steroid treatment rapidly reduced the number of proinflammatory CXCR3+ CD4+ T cells in the kidney by combining high-dimensional single-cell and morphological analyses of kidney biopsies from patients with antineutrophil cytoplasmic antibody (ANCA)-associated crescentic glomerulonephritis. Using an experimental model of crescentic glomerulonephritis, we show that the steroid-induced decrease in renal CD4+ T cells is a consequence of reduced T-cell recruitment, which is associated with an ameliorated disease course. Mechanistic in vivo and in vitro studies revealed that steroids act directly on renal tissue cells, such as tubular epithelial cells, but not on T cells, which resulted in an abolished renal expression of CXCL9 and CXCL10, as well as in the prevention of CXCR3+ CD4+ T-cell recruitment to the inflamed kidneys. Thus, we identified the CXCL9/10-CXCR3 axis as a previously unrecognized cellular and molecular target of glucocorticoids providing protection from immune-mediated pathology.
Morgantini C, Jager J, Li X, Levi L, Azzimato V, Sulen A, Barreby E, Xu C, Tencerova M, Näslund E, Kumar C, Verdeguer F, Straniero S, Hultenby K, Björkström NK, Ellis E, Rydén M, Kutter C, Hurrell T, Lauschke VM, Boucher J, Tomčala A, Krejčová G, Bajgar A and Aouadi M
| DOI: 10.1038/s42255-019-0044-9
Liver macrophages (LMs) have been proposed to contribute to metabolic disease through secretion of inflammatory cytokines. However, anti-inflammatory drugs lead to only modest improvements in systemic metabolism. Here we show that LMs do not undergo a proinflammatory phenotypic switch in obesity-induced insulin resistance in flies, mice and humans. Instead, we find that LMs produce non-inflammatory factors, such as insulin-like growth factor–binding protein 7 (IGFBP7), that directly regulate liver metabolism. IGFBP7 binds to the insulin receptor and induces lipogenesis and gluconeogenesis via activation of extracellular-signal-regulated kinase (ERK) signalling. We further show that IGFBP7 is subject to RNA editing at a higher frequency in insulin-resistant than in insulin-sensitive obese patients (90% versus 30%, respectively), resulting in an IGFBP7 isoform with potentially higher capacity to bind to the insulin receptor. Our study demonstrates that LMs can contribute to insulin resistance independently of their inflammatory status and indicates that non-inflammatory factors produced by macrophages might represent new drug targets for the treatment of metabolic diseases.
March-Riera, S;Wilson, AA;Bhatia, SN;Muhlberger, E;
| DOI: 10.1016/j.stemcr.2022.08.003
Liver damage and an exacerbated inflammatory response are hallmarks of Ebola virus (EBOV) infection. Little is known about the intrinsic response to infection in human hepatocytes and their contribution to inflammation. Here, we present an induced pluripotent stem cell (iPSC)-derived hepatocyte-like cell (HLC) platform to define the hepato-intrinsic response to EBOV infection. We used this platform to show robust EBOV infection, with characteristic ultrastructural changes and evidence for viral replication. Transcriptomics analysis revealed a delayed response with minimal early transcriptomic changes, followed by a general downregulation of hepatic function and upregulation of interferon signaling, providing a potential mechanism by which hepatocytes participate in disease severity and liver damage. Using RNA-fluorescence in situ hybridization (FISH), we showed that IFNB1 and CXCL10 were mainly expressed in non-infected bystander cells. We did not observe an inflammatory signature during infection. In conclusion, iPSC-HLCs are an immune competent platform to study responses to EBOV infection.
A RIPK1-regulated inflammatory microglial state in amyotrophic lateral sclerosis
Proceedings of the National Academy of Sciences of the United States of America
Mifflin, L;Hu, Z;Dufort, C;Hession, CC;Walker, AJ;Niu, K;Zhu, H;Liu, N;Liu, JS;Levin, JZ;Stevens, B;Yuan, J;Zou, C;
PMID: 33766915 | DOI: 10.1073/pnas.2025102118
Microglial-derived inflammation has been linked to a broad range of neurodegenerative and neuropsychiatric conditions, including amyotrophic lateral sclerosis (ALS). Using single-cell RNA sequencing, a class of Disease-Associated Microglia (DAMs) have been characterized in neurodegeneration. However, the DAM phenotype alone is insufficient to explain the functional complexity of microglia, particularly with regard to regulating inflammation that is a hallmark of many neurodegenerative diseases. Here, we identify a subclass of microglia in mouse models of ALS which we term RIPK1-Regulated Inflammatory Microglia (RRIMs). RRIMs show significant up-regulation of classical proinflammatory pathways, including increased levels of Tnf and Il1b RNA and protein. We find that RRIMs are highly regulated by TNFα signaling and that the prevalence of these microglia can be suppressed by inhibiting receptor-interacting protein kinase 1 (RIPK1) activity downstream of the TNF receptor 1. These findings help to elucidate a mechanism by which RIPK1 kinase inhibition has been shown to provide therapeutic benefit in mouse models of ALS and may provide an additional biomarker for analysis in ongoing phase 2 clinical trials of RIPK1 inhibitors in ALS.
Doke, T;Abedini, A;Aldridge, DL;Yang, YW;Park, J;Hernandez, CM;Balzer, MS;Shrestra, R;Coppock, G;Rico, JMI;Han, SY;Kim, J;Xin, S;Piliponsky, AM;Angelozzi, M;Lefebvre, V;Siracusa, MC;Hunter, CA;Susztak, K;
PMID: 35552540 | DOI: 10.1038/s41590-022-01200-7
Inflammation is an important component of fibrosis but immune processes that orchestrate kidney fibrosis are not well understood. Here we apply single-cell sequencing to a mouse model of kidney fibrosis. We identify a subset of kidney tubule cells with a profibrotic-inflammatory phenotype characterized by the expression of cytokines and chemokines associated with immune cell recruitment. Receptor-ligand interaction analysis and experimental validation indicate that CXCL1 secreted by profibrotic tubules recruits CXCR2+ basophils. In mice, these basophils are an important source of interleukin-6 and recruitment of the TH17 subset of helper T cells. Genetic deletion or antibody-based depletion of basophils results in reduced renal fibrosis. Human kidney single-cell, bulk gene expression and immunostaining validate a function for basophils in patients with kidney fibrosis. Collectively, these studies identify basophils as contributors to the development of renal fibrosis and suggest that targeting these cells might be a useful clinical strategy to manage chronic kidney disease.
