To navigate changes within a highly dynamic and complex environment, it is crucial to compare current visual representations of a scene to previously formed representations stored in memory. This process of mental comparison requires integrating information from multiple sources to inform decisions about changes within the environment. In the present article, we combine a novel systems factorial technology change detection task (Blunden et al.
View Article and Find Full Text PDFWe explored the generation of human induced pluripotent stem cells (iPSCs) solely through the transcriptional activation of endogenous genes by CRISPR activation (CRISPRa). Minimal number of human-specific guide RNAs targeting a limited set of loci were used with a unique cocktail of small molecules (CRISPRa-SM). iPSC clones were efficiently generated by CRISPRa-SM, expressed general and naive iPSC markers and clustered with high-quality iPSCs generated using conventional reprogramming methods.
View Article and Find Full Text PDFBackground: The advent of chimeric antigen receptor (CAR) T cell therapies has transformed the treatment of hematological malignancies; however, broader therapeutic success of CAR T cells has been limited in solid tumors because of their frequently heterogeneous composition. Stress proteins in the MICA and MICB (MICA/B) family are broadly expressed by tumor cells following DNA damage but are rapidly shed to evade immune detection.
Methods: We have developed a novel CAR targeting the conserved α3 domain of MICA/B (3MICA/B CAR) and incorporated it into a multiplexed-engineered induced pluripotent stem cell (iPSC)-derived natural killer (NK) cell (3MICA/B CAR iNK) that expressed a shedding-resistant form of the CD16 Fc receptor to enable tumor recognition through two major targeting receptors.
In the mammalian genome, the clustered protocadherin (cPCDH) locus provides a paradigm for stochastic gene expression with the potential to generate a unique cPCDH combination in every neuron. Here we report a chromatin-based mechanism that emerges during the transition from the naive to the primed states of cell pluripotency and reduces, by orders of magnitude, the combinatorial potential in the human cPCDH locus. This mechanism selectively increases the frequency of stochastic selection of a small subset of cPCDH genes after neuronal differentiation in monolayers, 10-month-old cortical organoids and engrafted cells in the spinal cords of rats.
View Article and Find Full Text PDFGenetic, epidemiologic, and biochemical evidence suggests that predisposition to Alzheimer's disease (AD) may arise from altered cholesterol metabolism, although the molecular pathways that may link cholesterol to AD phenotypes are only partially understood. Here, we perform a phenotypic screen for pTau accumulation in AD-patient iPSC-derived neurons and identify cholesteryl esters (CE), the storage product of excess cholesterol, as upstream regulators of Tau early during AD development. Using isogenic induced pluripotent stem cell (iPSC) lines carrying mutations in the cholesterol-binding domain of APP or APP null alleles, we found that while CE also regulate Aβ secretion, the effects of CE on Tau and Aβ are mediated by independent pathways.
View Article and Find Full Text PDFMounting evidence suggests that alterations in cholesterol homeostasis are involved in Alzheimer's disease (AD) pathogenesis. Amyloid precursor protein (APP) or multiple fragments generated by proteolytic processing of APP have previously been implicated in the regulation of cholesterol metabolism. However, the physiological function of APP in regulating lipoprotein homeostasis in astrocytes, which are responsible for cholesterol biosynthesis and regulation in the brain, remains unclear.
View Article and Find Full Text PDFDeveloping effective therapeutics for complex diseases such as late-onset, sporadic Alzheimer's disease (SAD) is difficult due to genetic and environmental heterogeneity in the human population and the limitations of existing animal models. Here, we used hiPSC-derived neurons to test a compound that stabilizes the retromer, a highly conserved multiprotein assembly that plays a pivotal role in trafficking molecules through the endosomal network. Using this human-specific system, we have confirmed previous data generated in murine models and show that retromer stabilization has a potentially beneficial effect on amyloid beta generation from human stem cell-derived neurons.
View Article and Find Full Text PDFPatient-specific induced pluripotent stem cells (iPSCs) derived from somatic cells provide a unique tool for the study of human disease, as well as a promising source for cell replacement therapies. One crucial limitation has been the inability to perform experiments under genetically defined conditions. This is particularly relevant for late age onset disorders in which in vitro phenotypes are predicted to be subtle and susceptible to significant effects of genetic background variations.
View Article and Find Full Text PDFLoss of dopaminergic neurons is primarily responsible for the onset and progression of Parkinson's disease (PD); thus, neuroprotective and/or neuroregenerative strategies remain critical to the treatment of this increasingly prevalent disease. Here we explore a novel approach to neurotrophic factor-based therapy by engineering zinc finger protein transcription factors (ZFP TFs) that activate the expression of the endogenous glial cell line-derived neurotrophic factor (GDNF) gene. We show that GDNF activation can be achieved with exquisite genome-wide specificity.
View Article and Find Full Text PDF