Free Bilirubin Induces Neuro-Inflammation in an Induced Pluripotent Stem Cell-Derived Cortical Organoid Model of Crigler-Najjar Syndrome

Abstract

Bilirubin-induced neurological damage (BIND), which might progress to kernicterus, occurs as a consequence of defects in the bilirubin conjugation machinery, thus enabling albumin-unbound free bilirubin (BF) to cross the blood–brain barrier and accumulate within. A defect in the UGT1A1 enzyme-encoding gene, which is directly responsible for bilirubin conjugation, can cause Crigler–Najjar syndrome (CNS) and Gilbert’s syndrome. We used human-induced pluripotent stem cell (hiPSC)-derived 3D brain organoids to model BIND in vitro and unveil the molecular basis of the detrimental effects of BF in the developing human brain. Healthy and patient-derived iPSCs were differentiated into day-20 brain organoids, and then stimulated with 200 nM BF. Analyses at 24 and 72 h post-treatment point to BF-induced neuro-inflammation in both cell lines. Transcriptome, associated KEGG, and Gene Ontology analyses unveiled the activation of distinct inflammatory pathways, such as cytokine–cytokine receptor interaction, MAPK signaling, and NFκB activation. Furthermore, the mRNA expression and secretome analysis confirmed an upregulation of pro-inflammatory cytokines such as IL-6 and IL-8 upon BF stimulation. This novel study has provided insights into how a human iPSC-derived 3D brain organoid model can serve as a prospective platform for studying the etiology of BIND kernicterus.

Genetically Modified Hepatocytes Targeting Bilirubin and Ammonia Metabolism for the Construction of Bioartificial Liver System

“…7 C). This finding was consistent with previous findings that free bilirubin had neurotoxicity [ 35 , 36 ]. Engineering of metabolic pathways to detoxify bilirubin has received little attentions in previous BAL studies.…”

Hemozoin induces Malaria via activation of DNA damage, p38 MAPK and Neurodegenerative Pathways in Human iPSC-derived Neuronal Model of Cerebral Malaria

“…2). Secretion of vascular endothelial growth factor (VEGF) and platelet derived growth factor subunit B (PDGFB), both belonging to the same protein family and reported to be associated with inflammation, were also enhanced 7 (Fig. 2a).…”

“…A majority of falciparum malaria research is based on clinical studies, which limits access to certain tissues such as the brain. Human derived induced pluripotent stem cells (iPSCs) have emerged as a relevant tool for modelling several diseases in-vitro 7,8 . iPSCs can be used for extensive studies related to disease pathogenesis, the impact of exogenous factors and the molecular targets of disease-modulating treatments.…”

Single cell data enables dissecting cell types present in bulk transcriptome data

“…Additionally, precursor cells such as oligodendrocyte precursor cells (3%) and neural stem cells (11%) were detected in the scRNA-seq data. The results from InstaPrism-based deconvolution of bulk organoid transcriptome data from our previous publication-Pranty et al 21 is presented as a pie chart in Figure 6c and depicts the proportions of cell types found in untreated brain organoids, the most abundant are Interneurons (15.2%). In another earlier study from our group, we developed a brain organoid model to study the molecular mechanisms associated with Nijmegen-Breakage syndrome (NBS) 22 .…”

“…Here, we introduce a pipeline for deconvolution of bulk organoid transcriptome data using scRNA-seq datasets of various tissues and demonstrate its performance with use cases of bulk transcriptome data from kidney 13 and brain organoids 22,21 employing publicly available (NCBI GEO) scRNA-seq kidney datasets GSE241302 and GSE202109 associated with studies by Shi et al 14 and McEvoy et al 15 and brain datasets GSE104276 associated with the study by Zhong et al 16 .…”