Peripheral blood gene expression as a novel genomic biomarker in complicated sarcoidosis
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ABSTRACT: Sarcoidosis, a systemic granulomatous syndrome invariably affecting the lung, typically spontaneously remits but in ~20% of cases progresses with severe lung dysfunction or cardiac and neurologic involvement (complicated sarcoidosis). Unfortunately, current biomarkers fail to distinguish patients with remitting (uncomplicated) sarcoidosis from other fibrotic lung disorders, and fail to identify individuals at risk for complicated sarcoidosis. We utilized genome-wide peripheral blood gene expression analysis to identify a gene signature distinguishing sarcoidosis from healthy controls, which also served as a molecular signature for complicated sarcoidosis.
Project description:Sarcoidosis, a systemic granulomatous syndrome invariably affecting the lung, typically spontaneously remits but in ~20% of cases progresses with severe lung dysfunction or cardiac and neurologic involvement (complicated sarcoidosis). Unfortunately, current biomarkers fail to distinguish patients with remitting (uncomplicated) sarcoidosis from other fibrotic lung disorders, and fail to identify individuals at risk for complicated sarcoidosis. We utilized genome-wide peripheral blood gene expression analysis to identify a gene signature distinguishing sarcoidosis from healthy controls, which also served as a molecular signature for complicated sarcoidosis. Total RNA was isolated from PBMCs using standard molecular biology protocols without DNA contamination or RNA degradation. Sample processing (e.g., cDNA generation, fragmentation, end labeling, hybridization to Affymetrix GeneChip Human Exon 1.0 ST arrays) was performed per manufacturer’s instructions. A total of 29 African descent American (AA) and 10 European descent American (EA) patients with sarcoidosis were included in the overall sarcoidosis cohort with 18 AA and 4 EA patients diagnosed with complicated sarcoidosis.
Project description:Sarcoidosis is a granulomatous disease of unknown cause. We performed single-cell RNA sequencing to identify the macrophages that comprise sarcoidosis granulomas.
Project description:Cutaneous sarcoidosis skin provides relatively non invasive access to granulomatous sarcoidosis tissue. Twenty participants were enrolled: 15 with active CS and 5 healthy volunteers. Microarray analyses comparing non-LS and healthy volunteer skin with LS showed several thousand genes differentially expressed
Project description:Growth hormone releasing hormone (GHRH) is a potent stimulator of growth hormone secretion from pituitary gland. Although GHRH is essential for growth of immune cells, the regulatory effects of its antagonist in granulomatous disease remains unknown. The goal is to evaluate the expression of GHRH receptor in human tissue with sarcoidosis granuloma and demonstrate the anti-inflammatory effects of MIA-602 (a GHRH antagonist) in in vitro and in vivo studies. Granulomatous reaction in the mouse lung was developed as previously described (PMID: 31921151). Mice were treated with 5 micrograms of MIA-602 (an GHRH antagonist) daily subcutanously. RNA from mouse lungs were extracted and RNASeq was perfomed.
Project description:Rationale: Chronic sarcoidosis is a complex granulomatous disease with limited treatment options that can progress over time. Understanding the molecular pathways contributing to disease would aid in new therapeutic development. Objectives: To understand if macrophages from non-resolving chronic sarcoidosis patients are predisposed to macrophage aggregation and granuloma formation, and if modulation of the underlying molecular pathways influence sarcoidosis granuloma formation. Methods: Macrophages were cultivated in vitro from isolated peripheral blood CD14+ monocytes and evaluated for spontaneous aggregation. Transcriptomics analyses, phenotypic and drug inhibitory experiments were performed on these monocyte-derived macrophages. Human skin biopsies from sarcoidosis patients and a myeloid Tsc2-specific sarcoidosis mouse model were analyzed for validatory experiments. Measurements and Main Results: Monocyte-derived macrophages from chronic sarcoidosis patients spontaneously formed extensive granulomas in vitro compared to healthy controls. Transcriptomic analyses separated healthy and sarcoidosis macrophages and identified an enrichment in lipid metabolic processes. In vitro patient granulomas, sarcoidosis mouse model granulomas, and those directly analyzed from lesional patient skin expressed an aberrant lipid metabolism profile and contained increased neutral lipids. Conversely, a combination of statins and cholesterol-reducing agents reduced granuloma formation both in vitro and in vivo in a sarcoidosis mouse model. Conclusions: Together, our findings show that altered lipid metabolism in sarcoidosis macrophages is associated with its predisposition to granuloma formation and suggest cholesterol-reducing therapies as a treatment option in patients.
Project description:Cardiac involvement is an important determinant of mortality amongst sarcoidosis patients. While granulomatous inflammation is a hallmark finding in cardiac sarcoidosis, the precise immune cell populations that comprise the granuloma remain unresolved. Furthermore, it is unclear how the cellular and transcriptomic landscape of cardiac sarcoidosis differs from other inflammatory heart diseases. We leveraged spatial transcriptomics (GeoMx DSP) and single nucleus RNA sequencing (snRNAseq) to elucidate the cellular and transcriptional landscape of cardiac sarcoidosis. Using GeoMX DSP technology, we compared the transcriptomal profile of CD68+ rich immune cell infiltrates in human cardiac sarcoidosis, giant cell myocarditis, and lymphocytic myocarditis. We performed snRNAseq of human cardiac sarcoidosis to identify immune cell types and examined their transcriptomic landscape and regulation. Using multi-channel immunofluorescence staining, we validated immune cell populations identified by snRNAseq, determined their spatial relationship, and devised an immunostaining approach to distinguish cardiac sarcoidosis from other inflammatory heart diseases. Despite overlapping histological features, spatial transcriptomics identified transcriptional signatures and associated pathways that robustly differentiated cardiac sarcoidosis from giant cell myocarditis and lymphocytic myocarditis. snRNAseq revealed the presence of diverse populations of myeloid cells in cardiac sarcoidosis with distinct molecular features. We identified GPNMB as a novel marker of multinucleated giant cells and predicted that the MITF family of transcription factors regulated this cell type. We also detected additional macrophage populations in cardiac sarcoidosis including HLA-DR+ macrophages, SYTL3+ macrophages and CD163+ resident macrophages. HLA-DR+ macrophages were found immediately adjacent to GPMMB+ giant cells, a distinct feature compared with other inflammatory cardiac diseases. SYTL3+ macrophages were located scattered throughout the granuloma and CD163+ macrophages, CD1c+ dendritic cells, non-classical monocytes, and T-cells were located at the periphery and outside of the granuloma. Finally, we demonstrate mTOR pathway activation is associated with proliferation and is selectively found in HLA-DR+ and SYLT3+ macrophages. In this study, we identified diverse populations of immune cells with distinct molecular signatures that comprise the sarcoid granuloma. These findings provide new insights into the pathology of cardiac sarcoidosis and highlight opportunities to improve diagnostic testing.
Project description:Sarcoidosis is a disease that affects multiple organ systems, with lung disease seen commonly and is the most frequent cause of sarcoidosis-related mortality. We investigated to compare protein expression in the lung from both bronchoalveolar lavage fluid (BAL) cells and fluid (BALF) in newly diagnosed patients with sarcoidosis. Mass spectral data acquisition was conducted on an Orbitrap Fusion instrument in data-dependent mode using either label-free (BALF) or label-based (intracellular) approach. We identified 4,306 high confidence intracellular proteins (probability >99%) with 272 differentially expressed proteins controlling for an FDR 5%. The protein map to several known canonical pathways including phagosome maturation, clathrin-mediated endocytic signaling, NRF-2 mediated oxidant stress response, The examination of BALF identified 1,192 proteins, xxx and xxx protein with differential expression between controls vs. sarcoidosis and progressive vs. non-progressive sarcoidosis respectively. Several of the proteins identified mapping to the differentially expressed proteins were also detected in the BALF.
Project description:This study used whole blood transcriptional signatures from patients with tuberculosis compared to those with similar pulmonary diseases, sarcoidosis, pneumonia and primary lung cancer. TB and sarcoidosis had similar signatures that were distinct from pneumonia and lung cancer. There were 16 TB, 25 sarcoidosis, 8 pneumonia, 8 lung cancer and 38 healthy controls
Project description:This study used whole blood transcriptional signatures from patients with tuberculosis compared to those with similar pulmonary diseases, sarcoidosis, pneumonia and primary lung cancer. TB and sarcoidosis had similar signatures that were distinct from pneumonia and lung cancer. There were 11 TB, 25 sarcoidosis, 6 pneumonia, 8 lung cancer and 52 healthy controls