Golgi fragmentation - One of the earliest organelle phenotypes in Alzheimer's disease neurons.

Alzheimer's disease (AD) is the most common cause of dementia, with no current cure. Consequently, alternative approaches focusing on early pathological events in specific neuronal populations, besides targeting the well-studied amyloid beta (Aß) accumulations and Tau tangles, are needed. In this study, we have investigated disease phenotypes specific to glutamatergic forebrain neurons and mapped the timeline of their occurrence, by implementing familial and sporadic human induced pluripotent stem cell models as well as the 5xFAD mouse model. We recapitulated characteristic late AD phenotypes, such as increased Aß secretion and Tau hyperphosphorylation, as well as previously well documented mitochondrial and synaptic deficits. Intriguingly, we identified Golgi fragmentation as one of the earliest AD phenotypes, indicating potential impairments in protein processing and post-translational modifications. Computational analysis of RNA sequencing data revealed differentially expressed genes involved in glycosylation and glycan patterns, whilst total glycan profiling revealed minor glycosylation differences. This indicates general robustness of glycosylation besides the observed fragmented morphology. Importantly, we identified that genetic variants in Sortilin-related receptor 1 (SORL1) associated with AD could aggravate the Golgi fragmentation and subsequent glycosylation changes. In summary, we identified Golgi fragmentation as one of the earliest disease phenotypes in AD neurons in various in vivo and in vitro complementary disease models, which can be exacerbated via additional risk variants in SORL1.

Generation of a gene-corrected isogenic control cell line from an Alzheimer's disease patient iPSC line carrying a A79V mutation in PSEN1.

Alzheimer's disease (AD) is a progressive and irreversible neurodegenerative disease causing neural cell degeneration and brain atrophy and is considered to be the most common form of dementia. We previously generated an induced pluripotent stem cell (iPSC) line from an AD patient carrying an A79V mutation in PSEN1 as an in vitro disease model. Here we generated a gene-corrected version from this hiPSC line by substituting the point mutation with the wild-type sequence. The reported A79V-GC-iPSCs line is a very useful resource in combination with the A79V-iPSC line in order to study pathological cellular phenotypes related to this particular mutation.

Generation of a gene-corrected isogenic control hiPSC line derived from a familial Alzheimer's disease patient carrying a L150P mutation in presenilin 1.

Mutations in the presenilin 1 (PSEN1) gene lead to the most aggressive form of familial Alzheimer's disease (AD). Human induced pluripotent stem cells (hiPSCs) derived from AD patients and subsequently differentiated can be used for disease modeling. We have previously generated a hiPSC line from a familial AD patient carrying a L150P point mutation in PSEN1. Here we used CRISPR/Cas9 gene editing to correct for the single base pair mutation. This gene-corrected line, L150P-GC-hiPSC, serves as an isogenic control to the mutant line for future investigation of mechanisms and cellular phenotypes altered by this specific PSEN1 mutation.

Derivation of induced pluripotent stem cells from a familial Alzheimer's disease patient carrying the L282F mutation in presenilin 1.

Mutations in presenilin 1 (PSEN1) lead to the most aggressive form of familial Alzheimer's disease (AD). Human induced pluripotent stem cells (hiPSCs) derived from AD patients can be differentiated and used for disease modeling. Here, we derived hiPSC from skin fibroblasts obtained from an AD patient carrying a L282F mutation in PSEN1. We transfected skin fibroblasts with episomal iPSC reprogramming vectors targeting human OCT4, SOX2, L-MYC, KLF4, NANOG, LIN28, and short hairpin RNA against TP53. Our hiPSC line, L282F-hiPSC, displayed typical stem cell characteristics with consistent expression of pluripotency genes and the ability to differentiation into the three germ layers.

Generation of induced pluripotent stem cells (iPSCs) from an Alzheimer's disease patient carrying an A79V mutation in PSEN1.

Skin fibroblasts were obtained from a 48-year-old presymptomatic woman carrying a A79V mutation in the presenilin 1 gene (PSEN1), causing Alzheimer's disease (AD). Induced pluripotent stem cell (iPSCs) were derived via transfection with episomal vectors carrying hOCT4, hSOX2, hKLF2, hL-MYC, hLIN28 and shTP53 genes. A79V-iPSCs were free of genomically integrated reprogramming genes, had the specific mutation but no additional genomic aberrancies, expressed the expected pluripotency markers and displayed in vitro differentiation potential to the three germ layers. The reported A79V-iPSCs line may be a useful resource for in vitro modeling of familial AD.

Generation of induced pluripotent stem cells (iPSCs) from an Alzheimer's disease patient carrying a M146I mutation in PSEN1.

Skin fibroblasts were obtained from a 46-year-old symptomatic man carrying a M146I mutation in the presenilin 1 gene (PSEN1), responsible for causing Alzheimer's disease (AD). Induced pluripotent stem cells (iPSCs) were derived via transfection with episomal vectors carrying hOCT4, hSOX2, hKLF2, hL-MYC, hLIN28 and shTP53 genes. M146I-iPSCs were free of genomically integrated reprogramming genes, had the specific mutation but no additional genomic aberrancies, expressed the expected pluripotency markers and displayed in vitro differentiation potential to the three germ layers. The reported M146I-iPSCs line may be a useful resource for in vitro modeling of familial AD.

Generation of induced pluripotent stem cells (iPSCs) from an Alzheimer's disease patient carrying a L150P mutation in PSEN-1.

Induced pluripotent stem cells (iPSCs) were generated from skin fibroblasts isolated from a 58-year old male with a L150P mutation in the presenilin 1 (PSEN-1) gene, which is responsible for the majority of familial cases of Alzheimer's disease (AD). The iPSCs were established by co-electroporation with episomal plasmids containing hOCT4, hSOX2, hL-MYC, hKLF4, hNANOG, hLIN28, and short hairpin RNA against TP53. The iPSCs contained the specific heterozygous mutation c.449C>T, had normal karyotype, expressed the expected pluripotency genes and displayed in vitro differentiation potential to the three germ layers. The iPSCs may be useful for studying familial AD pathology in vitro.

Induced Pluripotent Stem Cells Derived from Alzheimer's Disease Patients: The Promise, the Hope and the Path Ahead.

The future hope of generated induced pluripotent stem cells (iPS cells) from Alzheimer's disease patients is multifold. Firstly, they may help to uncover novel mechanisms of the disease, which could lead to the development of new and unprecedented drugs for patients and secondly, they could also be directly used for screening and testing of potential new compounds for drug discovery. In addition, in the case of familial known mutations, these cells could be targeted by use of advanced gene-editing techniques to correct the mutation and be used for future cell transplantation therapies. This review summarizes the work so far in regards to production and characterization of iPS cell lines from both sporadic and familial Alzheimer's patients and from other iPS cell lines that may help to model the disease. It provides a detailed comparison between published reports and states the present hurdles we face with this new technology. The promise of new gene-editing techniques and accelerated aging models also aim to move this field further by providing better control cell lines for comparisons and potentially better phenotypes, respectively.