Table 1 Update of all publications until now involving iPSCs approach in Alzheimer’s disease

FAMILIAL AD

Aβ; Astrocyte; Lipoprotein receptor

APP-KO astrocytes have reduced cholesterol and elevated levels of sterol regulatory element-binding protein (SREBP) target gene transcripts and proteins, which were both downstream consequences of reduced lipoprotein endocytosis.

Fong et al [36]

Sendai-virus

Dermal fibroblasts of the patient were obtained and a line of iPSCs was successfully generated using the Sendai virus (SeV) delivery system.

Wang et al [126]

Aβ; Tau; Amyloid; Disease modeling; Selective vulnerability

Both the generation of Aβ and the responsiveness of TAU to Aβ are affected by neuronal cell type, with rostral neurons being more sensitive than caudal neurons. Cell-autonomous factors may in part dictate the pattern of selective regional vulnerability in human neurons in AD.

Muratore et al [77]

Aβ; sAPPα; Microengraving

The authors have uncovered the dynamic range of secretion profiles of analytes from single iPSCs-derived neuronal and glial cells and have molecularly characterized subpopulations of these cells through immunostaining and gene expression analyses.

Liao et al [67]

Aβ; Proteolytic Enzyme; BACE1

Demonstrate that A673T, a protective allele of APP, reproducibly reduces amyloidogenic processing of APP and also mildly decreases Aβ aggregation. These effects could together have an additive or even synergistic impact on the risk of developing AD.

Maloney et al [71]

Disease model

Over differentiation time to mature neuronal fates, APP expression and levels of Aβ increase dramatically. In both immature and mature neuronal fates, the APPV717I mutation affects both β- and γ-secretase cleavage of APP. β-secretase cleavage of APP is elevated leading to generation of increased levels of both APPsβ and Aβ. This mutation alters the initial cleavage site of γ-secretase, resulting in an increased generation of both Aβ42 and Aβ38. An increase in levels of total and phosphorylated Tau is observed in neurons with the APPV717I mutation. Treatment with Aβ-specific antibodies early in culture reverses the phenotype of increased total Tau levels, implicating altered Aβ production in FAD neurons in this phenotype.

Muratore et al [76]

5XFAD mice; Oligodendrocyte; Protein-iPSC; Proteomic analysis

Protein-iPSCs differentiated into glial cells and decreased plaque depositions in the 5XFAD transgenic AD mouse model. Transplanted protein-iPSCs mitigated the cognitive dysfunction observed in these mice. Proteomic analysis revealed that oligodendrocyte-related genes were upregulated in brains injected with protein-iPSCs, providing new insights into the potential function of protein-iPSCs.

Cha et al [18]

Endocytosis; Transcytosis

Accumulation of β-CTFs of APP, but not Aβ, slow vesicle formation from an endocytic recycling compartment marked by the transcytotic GTPase Rab11. The authors confirm previous results that endocytosis is affected in AD and extend these to uncover a neuron-specific defect. Decreased lipoprotein endocytosis and transcytosis to the axon suggest that a neuron-specific impairment in endocytic axonal delivery of lipoproteins and other key materials might compromise synaptic maintenance in FAD.

Woodruff et al [128]

Mono- and bi-allelic sequence changes

The authors generated human iPSCs with heterozygous and homozygous dominant early onset AD causing mutations in APP(Swe) and PS1(M146 V) and derived cortical neurons, which displayed genotype-dependent disease-associated phenotypes.

Paquet et al [86]

Therapeutic potential; Macrophage-like cells

In vitro, expression of NEP2 but not anti-Aβ scFv enhanced the effect to reduce the level of soluble Aβ oligomer in the culture medium and to alleviate the neurotoxicity of Aβ. The authors observed significant reduction in the level of Aβ in the brain interstitial fluid following administration of iPSCs-ML/NEP2.

Takamatsu et al [122]

ASM; Lysosomal depletion

Reveal a novel mechanism of ASM pathogenesis in AD that leads to defective autophagy due to impaired lysosomal biogenesis and suggests that partial ASM inhibition is a potential new therapeutic intervention for the disease.

Lee et al [60]

Apoptosis; NPCs

Premature neuronal differentiation with decreased proliferation and increased apoptosis occurred in AD-iPSCs-derived-NPCs once neuronal differentiation was initiated, together with higher levels of Aβ42 and phosphorylated tau.

Yang et al [135]

L282F mutation in PS1

The authors transfected skin fibroblasts with episomal iPSCs reprogramming vectors targeting human OCT4, SOX2, L-MYC, KLF4, NANOG, LIN28, and short hairpin RNA against TP53.

Poon et al [89]

L150P mutation in PS1

This gene-corrected line, L150P-GC-hiPSCs, serves as an isogenic control to the mutant line for future investigation of mechanisms and cellular phenotypes altered by this specific PS1 mutation.

Poon et al [90]

Disease model; M146I mutation

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 FAD.

Li et al [64]

Disease model; A79V mutation

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.

Li et al [65]

L150P mutation

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.

Tubsuwan et al [123]

3 different mutations; GSM

Biomarker signatures obtained with such models are misleading and that human neurons derived from hiPSCs provide a unique signature that will more accurately reflect drug response in human patients and in cerebrospinal fluid biomarker changes observed during GSM treatment.

Liu et al [68]

Non integrating vectors

Neurons from mutant hiPSC lines express PS1-A246E mutations themselves and show AD-like biochemical features, that is, amyloidogenic processing of APP indicated by an increase in Aβ42/Aβ40 ratio.

Mahairaki et al [70]

NPCs

PS1 mutant fibroblasts and NPCs produced greater ratios of Aβ42 to Aβ40 relative to their control counterparts, with the elevated ratio even more apparent in PS1 NPCs than in fibroblasts.

Sproul et al [116]

Allelic series mutations;

FAD PS1 mutations do not act as simple loss of PS1 function but instead dominantly gain an activity toxic to some, but not all, PS1 functions.

Woodruff et al [129]

Proteolytic APP processing

The human NSC-derived neurons express the neuron-specific APP(695) splice variant, BACE1, and all members of the γ-secretase complex. They also exhibit a differentiation-dependent increase in Aβ secretion and respond to the pharmacotherapeutic modulation by anti-amyloidogenic compounds, such as γ-secretase inhibitors and nonsteroidal anti-inflammatory drugs.

Koch et al [54]

Aβ42 secretion

FAD-iPSCs-derived differentiated neurons have increased toxic Aβ42 secretion, recapitulating the molecular pathogenesis of mutant presenilins. Secretion of Aβ42 from these neurons sharply responds to γ secretase inhibitors and modulators, indicating the potential for identification and validation of candidate drugs.

Yagi et al [130]

Amyloid; Bodily secretions; Cognitive impairment

FAD-iPSCs-derived differentiated neurons have increased Aβ 42 secretion, recapitulating the molecular pathogenesis of mutant presenilins.

Yagi et al [131]

BFCN; BFCNs; Electrophysiology

Cell lines harboring the PS2 N141I mutation displayed an increase in the Aβ42/40 in iPSCs-derived BFCNs. Neurons derived from PS2 N141I lines generated fewer maximum number of spikes in response to a square depolarizing current injection.

Ortiz-Virumbrales et al [84]

Fibroblast library; DIAN

The authors reprogrammed a subset of the DIAN fibroblast lines into iPSCs lines.

Karch et al [52]

Aβ hypothesis; Anti-cancer drugs; Clinical trials; Semagacestat; γ-by products; γ-secretase inhibitors

Some semagacestat effects are clearly different from a phenotype caused by a loss of function of presenilins, core proteins in the γ-secretase complex. Semagacestat increases intracellular byproduct peptides, produced along with Aβ through serial γ-cleavage of βAPP, as well as intracellular long Aβ species, in cell-based and in vivo studies of AD model mice.

Tagami et al [109]

Cerebral organoids; Cdk5; Isogenic; Tauopathy

Significant reduction of phosphorylated tau and its seeding activity in the brain of double transgenic mice compared with the P301S mice. Synaptic loss and impaired LTP at hippocampal CA3 region of P301S mice were attenuated by blocking p25 generation. Blockade of p25 generation reduced levels of phosphorylated tau and increased expression of synaptophysin.

Seo et al [102]

3D organoids; Aβ; Tau; AD-GWAS; iMGLs

iMGLs develop in vitro similarly to microglia in vivo, and whole-transcriptome analysis demonstrates that they are highly similar to cultured adult and fetal human microglia.

Abud et al [1]

Aβ42/Aβ40 ratio; Alzheimerogen; Aβ; Aβ Herbicides; HCE; Triazines

Neurons derived from iPSCs obtained from a FAD patient (AβPP K724 N) produced more Aβ42 versus Aβ40 than neurons derived from healthy controls iPSCs (AβPP WT). Triazines enhanced Aβ42 production in both control and AD iPSCs-derived neurons. Triazines also shifted the cleavage pattern of alcadeinα, another γ-secretase substrate, suggesting a direct effect of triazines on γ-secretase activity.

Portelius et al [91]

BACE; Neuregulin; Amyloid

Subcellular compartmentalization allows BACE1 to cleave APP in the endosomal compartment and other non-amyloid substrates in non-endosomal compartments.

Ben et al [9]

Signaling events

Over a timeframe that mirrors human development, these progenitors give rise to functional lower and upper layer neurons.

Saurat et al [97]

Fibroblasts; Postmortem; Centenarian donors

The expression of molecules that play critical roles in late-onset neurodegenerative diseases by neurons differentiated from the centenarian-iPSCs was compared to that of neurons differentiated from iPSCs derived from FAD and familial Parkinson’s disease patients.

Yagi et al [132]

DS; Development of AD pathologies

Hyperphosphorylated tau protein, a pathological hallmark of AD, was found to be localized to cell bodies and dendrites in iPSCs-derived cortical neurons from Down syndrome patients, recapitulating later stages of the AD pathogenic process.

Shi et al [104]

SPORADIC AD

Aβ; Mitochondria

Neuronal cultures from some patients produced more reactive oxygen species and displayed higher levels of DNA damage. Patient-derived cells showed increased levels of oxidative phosphorylation chain complexes, whereas mitochondrial fission and fusion proteins were not affected.

Birnbaum et al [13]

PBMC; Homozygous APOE4 AD: ASUi003-A; non-demented control: ASUi004-A

hiPSCs maintained their original genotype, expressed pluripotency markers, exhibited a normal karyotype, and retained the ability to differentiate into cells representative of the three germ layers.

Brookhouser et al [14]

PBMCs;Homozygous APOE4 risk allele AD: ASUi001-A; non-demented control: ASUi002-A

hiPSCs maintained their original genotype, expressed pluripotency markers, exhibited a normal karyotype, and demonstrated the ability to differentiate into cells representative of the three germ layers.

Brookhouser et al [15]

Glucose MetS/T2DM; NMDA receptor

Redox-mediated posttranslational modification of brain proteins link Aβ and hyperglycaemia to cognitive dysfunction in MetS/T2DM and AD.

Akhtar et al [2]

Neurodegeneration; Pathology propagation; Tau oligomer seeds

Tau oligomers, but not monomers, induce accumulation of pathological, hyperphosphorylated tau. This effect was accompanied with neurite degeneration, loss of synapses, aberrant calcium homeostasis, imbalanced neurotransmitter release, and ultimately with neuronal death.

Usenovic et al [124]

SORL1 gene

The variation in SORL1 expression induction by BDNF is modulated by common genetic variants and can explain how genetic variation in this one locus can contribute to an individual’s risk of developing SAD.

Young et al [136]

Dermal fibroblasts; 82 year old female

The expression of p-tau and GSK3B, a physiological kinase of tau, in neuronal cells derived from AD-iPSCs. Treatment of neuronal cells differentiated from AD-iPSCs with an inhibitor of γ-secretase resulted in the down-regulation of p-tau.

Hossini et al [44]

BFCNs; ApoE3/E4 genotypes (AD-E3/E4)

BFCNs derived from AD-E3/E4 patients showed typical AD biochemical features evidenced by increased Aβ42/Aβ40 ratios. AD-E3/E4 neurons also exhibited altered responses to treatment with γ-secretase inhibitors compared to control BFCNs or neurons derived from patients with FAD.

Duan et al [28]

Frozen non-cryoprotected tissue; Autopsy cohort

Disease-specific iPSCs can be generated from readily available, archival biobanked tissue. This allows for rapid expansion of generating iPSCs with confirmed pathology as well as allowing access to rare patient variants that have been banked.

Sproul et al [117]

FAMILIAL AD AND SPORADIC AD

Aβ; GSK3B; Hyper phosphorylation; TAU pathology

Neurons from patients with FAD and patients with SAD showed increased phosphorylation of TAU protein at all investigated phosphorylation sites. Neurons derived from patients with FAD and patients with SAD exhibited higher levels of extracellular Aβ1–40 and Aβ1–42.

Ochalek et al [80]

Calcium homeostasis; Cytokine release; Lactate secretion; Mitochondrial metabolism; Oxidative stress; Aβ production

AD astrocytes manifest hallmarks of disease pathology, including increased Aβ production, altered cytokine release, and dysregulated Ca2 + homeostasis.

Oksanen et al [82]

LC-MS/MS; Biomarker; Proteomics

Alpha-1-acid glycoprotein (ORM1) was decreased in the culture media of AD-iPSCs-derived neurons, consistent with previous observations for AD patient cerebrospinal fluid, thus validating our new strategy.

Shirotani et al [113]

hiPSC-derived astrocyte model

Chemically defined and highly efficient model provides > 95% homogeneous populations of human astrocytes within 30 days of differentiation from cortical NPCs.

Jones et al [51]

Aβ; Neurotoxicity; PS1-A246E mutation

iPSCs lines were differentiated into neuronal precursors (iPSCs-NPCs) and neurons that were subjected to Aβ toxicity assays. Neurons derived from the FAD patient have a higher susceptibility to Aβ1–42 oligomers compared with neurons coming from healthy and sAD individuals.

Armijo et al [5]

Neuroprotective activity; Apigenin

The iPSCs-derived AD neurons demonstrated a hyper-excitable calcium signaling phenotype, elevated levels of nitrite, increased cytotoxicity and apoptosis, reduced neurite length and increased susceptibility to inflammatory stress challenge from activated murine microglia, in comparison to control neurons.

Balez et al [8]

Cellular model; Synaptotoxic effects of Aβ

Upon long-term cultivation, purified cells differentiated into mature neurons exhibiting the generation of action potentials and excitatory glutamatergic and inhibitory GABAergic synapses. Most interestingly, these iPSCs-derived human neurons were strongly susceptible to the synaptotoxic actions of Aβ.

Nieweg et al [79]

Neurotoxicity; Non-toxic mutants of Aβ42;

The non-toxic mutants of Aβ42 without the “toxic” turn could prevent the propagation process of the toxic conformer of Aβ42 resulting in suppression of the formation of the toxic oligomers.

Izuo et al [49]

Disease model

Aβ oligomers accumulated in iPSCs-derived neurons and astrocytes in cells from patients with a familial APP-E693Δ mutation and SAD, leading to endoplasmic reticulum (ER) and oxidative stress.

Kondo et al [55]

Duplication of the Aβ APP (Dp)

Direct relationship between APP proteolytic processing, but not Aβ, in GSK-3β activation and tau phosphorylation in human neurons. Neurons with the genome of one sAD patient exhibited the phenotypes seen in familial AD samples.

Israel et al [48]

Drug evaluation; Preclinical; Tissue therapy; PD; DM; DMD

Each iPSCs line exhibited an intense alkaline phosphatase activity, expression of pluripotent markers, and the potential to differentiate into all three embryonic germ layers.

Jang et al [50]

DOES NOT SPECIFY

Drug screening; Parkinsonism; Tauopathies; Triple MAPT-mutant

Mutant neurons expressed pathogenic 4R and phosphorylated TAU, endogenously triggered TAU aggregation, and had increased electrophysiological activity.

García-León et al [37]

DS; Hsa21 trisomy; Aβ; Cortical neurogenesis;

Tau phosphorylation

Cortical neuronal differentiation shows that an increased APP gene dosage is responsible for increased β-amyloid production, altered Aβ42/40 ratio, and deposition of the pyroglutamate (E3)-containing amyloid aggregates, but not for several tau-related AD phenotypes or increased apoptosis.

Ovchinnikov [85] et al

3D culture; Bioinformatics; Proteomic

Similar analysis of post-mortem AD brain tissue revealed significant alteration in proteins involved in oxidative stress, neuro-inflammation, along with proteins related to axonal injury.

Chen et al [21]

Leptomeningeal cell; Postmortem

Leptomeningeal-derived hiPSCs lines can be generated from fresh and frozen leptomeninges, are pluripotent, and retain the karyotype of the starting cell population.

Rose et al [96]

SORL1 expression; Null, one, or two copies of the APOE4 allele

Reduced SORL1 expression only in NSCs of a patient carrying two copies of APOE4 allele with increased Aβ/SORL1 localization along the degenerated neurites. SORL1 binding to APP was largely compromised; this could be almost completely reversed by γ-secretase (but not β-secretase) inhibitor treatment.

Zollo et al [142]

PD; Cortical neurons; Macrophage; Microglia; Neuroinflammation

Co-cultures retain neuronal maturity and functionality for many weeks. Co-culture microglia express key microglia-specific markers and neurodegenerative disease-relevant genes, develop highly dynamic ramifications, and are phagocytic. Upon activation, they become more amoeboid, releasing multiple microglia-relevant cytokines.

Haenseler et al [42]

AICD; APP; CTF; Aβ;p3 peptide

The 42:40 ratio was highest for Aβ’, followed by Aβ and then p3. Mass spectrometry analysis of APP intracellular domains revealed differential processing of APP-C83, APP-C89, and APP-C99 by γ-secretase already at the ε-cleavage stage.

Siegel et al [114]

PBMCs; Yamanaka factors

The transgene-free iPSCs line showed pluripotency verified by immunofluorescent staining for pluripotency markers, and the iPSCs line was able to differentiate into the 3 germ layers in vivo. The iPSCs line also showed normal karyotype.

Zhang et al [140]

Down syndrome; Aβ; Ivermectin; Phenotypic screening; Selamectin

The authors identified the avermectins, commonly used as anthelmintic, as compounds that increase the relative production of short Aβ peptides at the expense of longer, potentially more toxic peptides. Further studies demonstrated that this effect is not due to an interaction with the core γ-secretase responsible for Aβ production.

Brownjohn et al [16]

APP; Aβ42; BACE2; Aβ DS; ETS2; RCAN1; TMED10

In vitro generated DS neural cells have abnormal metabolism of Aβ manifested by increased secretion and accumulation of Aβ granules of Aβ42 pathological isoform with upregulated expression of the APP gene.

Dashinimaev et al [23]

hTFAM; Oxidative stress; mtDNA

Expression of hTFAM significantly improved cognitive function, reducing accumulation of both 8-oxoguanine, an oxidized form of guanine, in mtDNA and intracellular Aβ in 3xTg-AD mice and increasing expression of transthyretin, known to inhibit Aβ aggregation.

Oka et al [81]

Gene-corrected version; Substituting mutation with wild-type sequence A79V mutation in PSEN1

The reported A79V-GC-iPSCs line is a very useful resource in combination with the A79V-iPSCs line in order to study pathological cellular phenotypes related to this particular mutation.

Pires et al [88]

HLC; Gene CR1

The iPSCs retained the CR1 CNV, and comparative transcriptome analyses with the human ESCs line H1 revealed a Pearson correlation of 0.956 for AD1-CR10 and 0.908 for AD1-CR14.

Schroter et al [100]

Episomal plasmids; HLC; Missense mutation TREM2

Human lymphoblast cells from a female patient possessing the mis-sense mutation TREM2 p.R47H were used to generate integration-free iPSCs employing episomal plasmids expressing OCT4, SOX2, NANOG, LIN28, c-MYC and L-MYC.

Schroter et al [98]

PBMC; Memory deficit

Integration-free CytoTune-iPS Sendai Reprogramming factors were introduced to PBMC to convert them to iPSCs without retention of virus. Three germ layer differentiation was induced to demonstrate the pluripotency of these iPSCs.

Lee et al [59]

Disease model; Human lymphoblast cells; TREM2 p.R47H variant

Human lymphoblast cells from a male patient expressing the TREM2p.R47H variant were used to generate integration-free iPS cells employing episomalplasmids expressing OCT4, SOX2, NANOG, LIN28, c-MYC and L-MY

Schroter et al [99]

Apoptosis; Kinase inhibitors; TRAIL

Wortmannin resulted in disappearance of phosphorylated AKT and activation of the main effector caspase-3 in iPSCs. These results clearly demonstrate for the first time that PI3K-AKT represents a highly essential survival-signaling pathway in iPSCs.

Hossini et al [45]

DS; MSC; Amniotic fluid

DS-iPSC derived neural cells can serve as an ideal cellular model of DS and AD and have potential for high-throughput screening of candidate drugs. Bdph may benefit DS or AD treatment by scavenging Aβ aggregates and NFTs.

Chang et al [19]

3D culture; Mechanotransduction

3D in vitro model has higher resemblance to the AD pathology than conventional 2D cultures and could be used in further studies of the disease.

Zhang et al [139]

Aβ; Glutamatergic; In vitro model

Administration of such Aβ oligomers yielded signs of the disease, including cell culture age-dependent binding of Aβ and cell death in the glutamatergic populations. Aβ-induced toxicity was selective for glutamatergic rather than GABAeric neurons present in our cultures.

Vazin et al [125]

GCSF; Aβ-induced

Demonstrate an improvement of memory and neurobehavioral function with GCSF in Aβ-induced AD model in rats.

Prakash et al [92]

Drug evaluation; Forebrain marker; Neocortical markers

The iPSCs cell-derived neuronal cells also expressed APP, β-secretase, and γ-secretase components, and were capable of secreting Aβ into the conditioned media. Aβ production was inhibited by β-secretase inhibitor, γ-secretase inhibitor (GSI), and an NSAID; however, there were different susceptibilities to all three drugs between early and late differentiation stages.

Yahata et al [133]