Project description:The application potential of human induced pluripotent stem cells (hiPSC) derived human retinal organoids (HRO) relies on the robustness and transferability of the methodology for their generation. Standardized strategies and parameters to effectively assess, compare and optimize organoid protocols have been started to be established, but are not completed yet. To advance this, we explored the efficiency and reliability of a differentiation protocol that facilitates retina generation by formation of neuroepithelial cysts from hiPSC clusters. Here, we tested seven different hiPSC lines, which reproducibly generated HROs. Histologic and ultrastructural analyses support regulated HRO differentiation and maturation. The different hiPSC lines appeared to be a larger source of variance than experimental rounds. Whereas previous reports showed that HRO in several other protocols contain a rather low numbers of cones compared to rods, HROs derived by the cyst protocol consistently are cone-richer and with an comparable ratio of cones, rods, and Müller glia. Additionally, we devised a potential strategy to systematically evaluate different protocols side-by-side through parallel differentiation from the same hiPSC batches: The cyst-protocol was compared to a conceptually different protocol based on cell aggregate formation from single hiPSCs. Comparison of four hIPSC lines showed that both protocols reproduced key characteristics of retinal epithelial structure and cell composition, but the cyst-protocol provided a higher HRO yield. Further, while cyst-derived HROs maintained stable at least up to date 250, whereas single hiPSC-derived HROs showed spontaneous pathologic changes already by day 200. Overall, our data provide insight into the efficiency, reproducibility, and stability of the cyst-protocol for HRO generation, which will be useful for further organoid system optimization, as well as basic and translational research applications.
Project description:To investigate the heterogeneity during the neuroepithelial stage of organoid development, we performed a multiome experiment on day 15-18 old brain organoids
Project description:Here we assess the reliability of human cortical spheroid differentiation cultured in xeno-free, feeder-free conditions. We find high reliability in differentiation across multiple hiPSC lines as well as across experiments, and we anticipate that this directed differentiation approach will be useful for large scale generation of brain-region specific spheroids and disease modeling.
Project description:Dysfunctional paracrine signaling through Pannexin 1 (PANX1) channels is linked to several adult neurological pathologies and emerging evidence suggests that PANX1 plays an important role in human brain development. It remains unclear how early PANX1 influences brain development, or how loss of PANX1 alters the developing human brain. Using a cerebral organoid model of early human brain development, we find that PANX1 is expressed at all stages of organoid development from neural induction through to neuroepithelial expansion and maturation. Interestingly, PANX1 cellular distribution and subcellular localization changes dramatically throughout cerebral organoid development. During neural induction, PANX1 becomes concentrated at the apical membrane domain of neural rosettes where it co-localizes with several apical membrane adhesion molecules. During neuroepithelial expansion, PANX1-/- organoids are significantly smaller than control and exhibit significant gene expression changes related to cell adhesion, WNT signaling and non-coding RNAs. As cerebral organoids mature, PANX1 expression is significantly upregulated and is primarily localized to neuronal populations outside of the ventricular-like zones. Ultimately, PANX1 protein can be detected in all layers of a 21-22 post conception week human fetal cerebral cortex. Together, these results show that PANX1 is dynamically expressed by numerous cell types throughout embryonic and early fetal stages of human corticogenesis and loss of PANX1 compromises neuroepithelial expansion due to dysregulation of cell-cell and cell-matrix adhesion, perturbed intracellular signaling, and changes to gene regulation.
Project description:To elucidate the molecular pathways that modulate renal cyst growth in autosomal dominant polycystic kidney disease (ADPKD) Keywords: Disease state analysis We performed global gene profiling on renal cysts of different size (small cysts: less than 1 ml, n=5; medium cysts: between 10-25 ml, n=5; large cysts: greater than 50 ml, n=3) and minimally cystic tissue (MCT, n=5) from five PKD1 polycystic kidneys. Additionally, non-cancerous renal cortical tissue from three nephrectomized kidneys with isolated renal cell carcinoma was used as normal control tissue (n=3). This dataset is part of the TransQST collection.
Project description:Autosomal dominant polycystic liver disease (ADPLD) is caused by mutations in PRKCSH, SEC63, and LRP5, while autosomal dominant polycystic kidney disease (ADPKD) is caused by mutations in PKD1, and PKD2. Liver cyst development in these disorders is explained by somatic loss-of-heterozygosity (LOH) of the wild type allele in the developing cyst. We hypothesize that we can use this mechanism to identify novel disease genes that reside in LOH regions. In this study, we aim to map abnormal genomic regions using high-density SNP microarrays to find novel polycystic liver disease genes. We collected 46 cysts from 23 patients with polycystic or sporadic hepatic cysts, and analyzed DNA from those cysts using high-resolution microarray (n=24) or Sanger sequencing (n=22). We here focused on regions of homozygosity on the autosomes (>3.0Mb), and large CNVs (>1.0Mb). We found frequent LOH in PRKCSH (22/29), and PKD1/PKD2 (2/3) cysts of patients with known heterozygous germline variants in the respective genes. In the total cohort, 12/23 patients harbored abnormalities outside of familiar areas. In individual ADPLD cases, we identified germline events: a 2q13 complex rearrangement resulting in BUB1 haploinsufficiency, a 47XXX karyotype, chromosome 9q copy number loss, and LOH on chromosome 3p. The latter region was overlapping with an LOH region identified in two other cysts. Unique germline and somatic abnormalities occur frequently in and outside of known genes underlying cysts. Each liver cyst has a unique genetic makeup. LOH driver gene BUB1 may imply germline causes of genetic instability in PLD. 24 liver cysts from 23 patients