Patched 1 (PTCH1) is the primary receptor for the sonic hedgehog (SHH) ligand and negatively regulates SHH signalling, an essential pathway in human embryogenesis. Loss-of-function mutations in PTCH1 are associated with altered neuronal development and the malignant brain tumour medulloblastoma. As a result of differences between murine and human development, molecular and cellular perturbations that arise from human PTCH1 mutations remain poorly understood.
View Article and Find Full Text PDFPromiscuous activity of the Streptococcus pyogenes DNA nuclease CRISPR-Cas9 can result in destruction of a successfully modified sequence obtained by templated repair of a Cas9-induced DNA double-strand break. To avoid re-cutting, additional target-site-disruptions (TSDs) are often introduced on top of the desired base-pair alteration in order to suppress target recognition. These TSDs may lower the efficiency of introducing the intended mutation and can cause unexpected phenotypes.
View Article and Find Full Text PDFAims: Acute myocardial infarction rapidly increases blood neutrophils (<2 h). Release from bone marrow, in response to chemokine elevation, has been considered their source, but chemokine levels peak up to 24 h after injury, and after neutrophil elevation. This suggests that additional non-chemokine-dependent processes may be involved.
View Article and Find Full Text PDFDirecting the fates of human pluripotent stem cells (hPSC) to generate a multitude of differentiated cell types allows the study of the genetic regulation of human development and disease. The translational potential of hPSC is maximized by exploiting CRISPR to silence or activate genes with spatial and temporal precision permanently or reversibly. Here, we summarize the increasingly refined and diverse CRISPR toolkit for the latter forms of gene perturbation in hPSC and their downstream applications.
View Article and Find Full Text PDFPrecise gene editing of mitochondrial DNA (mtDNA) is essential for the generation of model systems to study rare mitochondrial diseases but was long deemed impossible - until now. A recent publication by Mok et al. describes a gene editing tool capable of installing point mutations in mtDNA, and it does not involve CRISPR.
View Article and Find Full Text PDFThe pervasive nature of RNA polymerase II (Pol II) transcription requires efficient termination. A key player in this process is the cleavage and polyadenylation (CPA) factor PCF11, which directly binds to the Pol II C-terminal domain and dismantles elongating Pol II from DNA in vitro. We demonstrate that PCF11-mediated termination is essential for vertebrate development.
View Article and Find Full Text PDFFanconi anemia (FA) is a cancer predisposition syndrome characterized by congenital abnormalities, bone marrow failure, and hypersensitivity to aldehydes and crosslinking agents. For FA patients, gene editing holds promise for therapeutic applications aimed at functionally restoring mutated genes in hematopoietic stem cells. However, intrinsic FA DNA repair defects may obstruct gene editing feasibility.
View Article and Find Full Text PDFHERV-K HML-2 (HK2) has been proliferating in the germ line of humans at least as recently as 250,000 years ago, with some integrations that remain polymorphic in the modern human population. One of the solitary HK2 LTR polymorphic integrations lies between exons 17 and 18 of , a gene that affects dopaminergic activity and is thus related to addiction. Here we show that this antisense HK2 integration (namely RASGRF2-int) is found more frequently in persons who inject drugs compared with the general population.
View Article and Find Full Text PDFTranscription factor (TF) networks determine cell-type identity by establishing and maintaining lineage-specific expression profiles, yet reconstruction of mammalian regulatory network models has been hampered by a lack of comprehensive functional validation of regulatory interactions. Here, we report comprehensive ChIP-Seq, transgenic and reporter gene experimental data that have allowed us to construct an experimentally validated regulatory network model for haematopoietic stem/progenitor cells (HSPCs). Model simulation coupled with subsequent experimental validation using single cell expression profiling revealed potential mechanisms for cell state stabilisation, and also how a leukaemogenic TF fusion protein perturbs key HSPC regulators.
View Article and Find Full Text PDFThe neuromuscular junction (NMJ) consists of a tripartite synapse with a presynaptic nerve terminal, Schwann cells that ensheathe the terminal bouton, and a highly specialized postsynaptic membrane. Synaptic structural integrity is crucial for efficient signal transmission. Congenital myasthenic syndromes (CMSs) are a heterogeneous group of inherited disorders that result from impaired neuromuscular transmission, caused by mutations in genes encoding proteins that are involved in synaptic transmission and in forming and maintaining the structural integrity of NMJs.
View Article and Find Full Text PDFDendritic cell (DC) maturation is a tightly regulated process that requires coordinated and timed developmental cues. Here we investigate whether microRNAs are involved in this process. We identify microRNAs in mouse GM-CSF-generated, monocyte-related DC (GM-DC) that are differentially expressed during both spontaneous and LPS-induced maturation and characterize M-CSF receptor (M-CSFR), encoded by the Csf1r gene, as a key target for microRNA-mediated regulation in the final step toward mature DC.
View Article and Find Full Text PDF