Baseline and Disease-Induced Transcriptional Profiles in Children with Sickle Cell Disease

Abstract

Acute chest syndrome (ACS) is a significant cause of morbidity and mortality in sickle cell disease (SCD), but preventive, diagnostic, and therapeutic options are limited. Further, ACS and acute vasoccclusive pain crises (VOC) have overlapping features, which causes diagnostic dilemmas. We explored changes in gene expression profiles among patients with SCD hospitalized for VOC and ACS episodes to better understand ACS disease pathogenesis. Whole blood RNA-Seq was performed for 20 samples from children with SCD at baseline and during a hospitalization for either an ACS (n = 10) or a VOC episode (n = 10). Respiratory viruses were identified from nasopharyngeal swabs. Functional gene analyses were performed using modular repertoires, IPA, Gene Ontology, and NetworkAnalyst 3.0. The VOC group had a numerically higher percentage of female, older, and hemoglobin SS participants compared to the ACS group. Viruses were detected in 50% of ACS cases and 20% of VOC cases. We identified 3004 transcripts that were differentially expressed during ACS episodes, and 1802 transcripts during VOC episodes. Top canonical pathways during ACS episodes were related to interferon signaling, neuro-inflammation, pattern recognition receptors, and macrophages. Top canonical pathways in patients with VOC included IL-10 signaling, iNOS signaling, IL-6 signaling, and B cell signaling. Several genes related to antimicrobial function were down-regulated during ACS compared to VOC. Gene enrichment nodal interactions demonstrated significantly altered pathways during ACS and VOC. A complex network of changes in innate and adaptive immune gene expression were identified during both ACS and VOC episodes. These results provide unique insights into changes during acute events in children with SCD.

Transcriptomic gene profiles in an ex vivo model of erythropoiesis to unravel molecular pathomechanisms of Sickle Cell Disease

“…T-cell lymphopenia-associated inflammatory responses have been previously linked to the inactivation of PI3Kδ and PI3Kγ 27 , genes that were found to be downregulated in a previous 25 meta-analysis in SCD. Concomitant suppression of genes related to adaptive immune responses (B and T cell signalling) was also observed during the two complications of SCD, acute chest syndrome (ACS) and acute vaso-occlusive pain crises (VOC) in the study from Creary et al 8 We found Th1 and Th2 cell differentiation and Th17 cell differentiation to be significantly enriched downregulated KEGG pathways for treated SCD patients in comparison to HC (Figure 3 and Supplementary Figure 3). This result might suggest a contribution to the altered immune response, potentially leading to an increased risk of severe bacterial infections among SCD patients.…”

Transcriptomic gene profiles in anex vivomodel of erythropoiesis to unravel molecular pathomechanisms of Sickle Cell Disease

“…T-cell lymphopenia–associated inflammatory responses have been previously linked to the inactivation of PI3Kδ and PI3Kγ 37 , genes that were found to be downregulated in a previous 16 meta-analysis. Concomitant suppression of genes related to adaptive immune responses (B and T cell signalling) was also observed during the two complications of SCD, acute chest syndrome (ACS) and acute vaso-occlusive pain crises (VOC) in the study from Creary et al 14 . We found Th1 and Th2 cell differentiation and Th17 cell differentiation to be significantly enriched downregulated KEGG pathways for treated SCD patients in comparison to healthy controls (Figure 3A-C).…”

“…A better understanding of SCD pathophysiology and its complex manifestation is needed to develop targeted new treatment modalities that may also be more widely available to patients 14 . To this end, we analysed gene expression profiles from children with SCD, treated with HU or untreated, in comparison to healthy controls in an erythropoiesis in vitro model.…”

“…Top platelet-abundant genes included platelet derived growth factor receptor alpha (PDGFRA), myosin light chain kinase (MYLK), platelet factor 4 variant 1 (PF4V1), 5'-aminolevulinate synthase 2 (ALAS2), histone cluster 1, H2bg (HIST1H2BG) and solute carrier family 24 member 3 (SLC24A3) 13 . Study from Creary et al 14 explored changes in gene expression profiles via whole blood RNA-Seq among patients with SCD hospitalized for acute chest syndrome (ACS) and acute vaso-occlusive pain crises (VOC) episodes. Top differentially expressed genes included CD177 molecule (CD177), caspase 5 (CASP5), suppressor of cytokine signalling 3 (SOCS3), free fatty acid receptor 3 (FFAR3), GRAM domain containing 1C (GRAMD1C) and annexin A3 (ANXA3), whereas top canonical pathways identified in ACS were interferon signalling, pattern recognition receptors, neuroinflammation, macrophages and in VOC were related to IL-10 signalling, iNOS signalling, IL-6 signalling and B cell signalling 14 .…”

“…Study from Creary et al 14 explored changes in gene expression profiles via whole blood RNA-Seq among patients with SCD hospitalized for acute chest syndrome (ACS) and acute vaso-occlusive pain crises (VOC) episodes. Top differentially expressed genes included CD177 molecule (CD177), caspase 5 (CASP5), suppressor of cytokine signalling 3 (SOCS3), free fatty acid receptor 3 (FFAR3), GRAM domain containing 1C (GRAMD1C) and annexin A3 (ANXA3), whereas top canonical pathways identified in ACS were interferon signalling, pattern recognition receptors, neuroinflammation, macrophages and in VOC were related to IL-10 signalling, iNOS signalling, IL-6 signalling and B cell signalling 14 . Desai et al 15 identified and validated the association of a circulating genome-wide gene expression profile with poor outcomes in 3 cohorts of SCD based on peripheral blood mononuclear cell (PBMC) transcriptomes.…”