scholarly journals Progress in the molecular mechanisms of genetic epilepsies using patient-induced pluripotent stem cells

2018 ◽  
Vol 3 (3) ◽  
pp. 331-339 ◽  
Author(s):  
Ruijiao Zhou ◽  
Guohui Jiang ◽  
Xin Tian ◽  
Xuefeng Wang
Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Shailaja Rao ◽  
Qian Zhang ◽  
Haruto Uchino ◽  
Arjun Pendharkar ◽  
Michelle Cheng ◽  
...  

Background: Moyamoya disease (MMD) is a rare, progressive steno-occlusive cerebrovascular disorder of the internal carotid artery, leading to stroke. Affected arteries exhibit thickened intima with depleted elastic lamina and media, indicating a dysfunction of the vascular smooth muscle cells (VSMCs) and endothelial cells (ECs). However the pathogenesis of the disease is still unclear. We aim to address this gap in knowledge by using patient derived induced pluripotent stem cells (iPSCs), to generate VSMCs and ECs. Methods: Peripheral blood mononuclear cells (PBMCs) from controls and MMD patients (n=3 per group) were used for generating iPSCs. VSMC functionality was measured by collagen gel contraction assay and scratch assay. EC proliferative function was assessed by BrDU incorporation assay, and its migration capacity was evaluated by scratch assay and in vitro tube formation. VSMCs and ECs were also exposed to either hydrogen peroxide (H2O2) or normoxia/ hypoxia model (1%O 2 ) to investigate how cells respond to these insults. Hypoxia inducible factor 1α (HIF1α) activation was determined using western blot. Results: MMD VSMCs trended towards being more contractile and migrating faster than control VSMCs, in response to 10%FBS or SDF1α. On the other hand, MMD ECs migrated slower than control ECs in response to 10%FBS (p=0.0081) or VEGF (p=0.0072). MMD ECs also formed lesser tubes and exhibited fewer branch points when compared to controls. The rate of EC proliferation was similar between both groups. Cell death assays indicate that MMD VSMCs and ECs were more sensitive to the deleterious effects of H2O2 exposure when compared to control cells. Interestingly, MMD VSMCs had elevated HIF1α protein expression in normoxia, which was further increased after hypoxia. Conclusions: Our preliminary results indicate that both MMD VSMCs and ECs are dysfunctional and may be related to the elevated basal expression of HIF1α, possibly contributing to MMD pathology. We are currently investigating the interactions between VSMCs and ECs in MMD compared with controls using co-cultures. Ongoing studies also include transcriptome analysis of these differentiated cells, which will advance the understanding of the cellular and molecular mechanisms underlying MMD.


2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Xinchao Hu ◽  
Chengyuan Mao ◽  
Liyuan Fan ◽  
Haiyang Luo ◽  
Zhengwei Hu ◽  
...  

Parkinson’s disease (PD) is the second most common neurodegenerative disease. The molecular mechanisms of PD at the cellular level involve oxidative stress, mitochondrial dysfunction, autophagy, axonal transport, and neuroinflammation. Induced pluripotent stem cells (iPSCs) with patient-specific genetic background are capable of directed differentiation into dopaminergic neurons. Cell models based on iPSCs are powerful tools for studying the molecular mechanisms of PD. The iPSCs used for PD studies were mainly from patients carrying mutations in synuclein alpha (SNCA), leucine-rich repeat kinase 2 (LRRK2), PTEN-induced putative kinase 1 (PINK1), parkin RBR E3 ubiquitin protein ligase (PARK2), cytoplasmic protein sorting 35 (VPS35), and variants in glucosidase beta acid (GBA). In this review, we summarized the advances in molecular mechanisms of Parkinson’s disease using iPSC models.


2019 ◽  
Vol 119 (09) ◽  
pp. 1461-1470 ◽  
Author(s):  
Ponthip Mekchay ◽  
Praewphan Ingrungruanglert ◽  
Kanya Suphapeetiporn ◽  
Darintr Sosothikul ◽  
Wilawan Ji-au ◽  
...  

AbstractBernard–Soulier syndrome (BSS) is a hereditary macrothrombocytopenia caused by defects in the glycoprotein (GP) Ib-IX-V complex. The mechanism of giant platelet formation remains undefined. Currently, megakaryocytes (MKs) can be generated from induced pluripotent stem cells (iPSCs) to study platelet production under pharmacological or genetic manipulations. Here, we generated iPSC lines from two BSS patients with mutations in different genes (GP1BA and GP1BB: termed BSS-A and BSS-B, respectively). The iPSC-derived MKs and platelets were examined under electron microscopy and stained by immunofluorescence to observe proplatelet formation and measure platelet diameters which were defined by circumferential tubulin. BSS-iPSCs produced abnormal proplatelets with thick shafts and tips. In addition, compared with the normal iPSCs, the diameters were larger in platelets derived from BSS-A and BSS-B with the means ± standard deviations of 4.34 ± 0.043 and 3.88 ± 0.045 µm, respectively (wild-type iPSCs 2.61 ± 0.025 µm, p < 0.001). Electron microscopy revealed giant platelets with the abnormal demarcation membrane system. Correction of BSS-A and BSS-B-iPSCs using lentiviral vectors containing respective GP1BA and GP1BB genes improved proplatelet structures and platelet ultrastructures as well as reduced platelets sizes. In conclusion, the iPSC model can be used to explore molecular mechanisms and potential therapy for BSS.


Cells ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2698
Author(s):  
Ishnoor Sidhu ◽  
Sonali P. Barwe ◽  
Raju K. Pillai ◽  
Anilkumar Gopalakrishnapillai

In vitro modeling of hematological malignancies not only provides insights into the influence of genetic aberrations on cellular and molecular mechanisms involved in disease progression but also aids development and evaluation of therapeutic agents. Owing to their self-renewal and differentiation capacity, induced pluripotent stem cells (iPSCs) have emerged as a potential source of short in supply disease-specific human cells of the hematopoietic lineage. Patient-derived iPSCs can recapitulate the disease severity and spectrum of prognosis dictated by the genetic variation among patients and can be used for drug screening and studying clonal evolution. However, this approach lacks the ability to model the early phases of the disease leading to cancer. The advent of genetic editing technology has promoted the generation of precise isogenic iPSC disease models to address questions regarding the underlying genetic mechanism of disease initiation and progression. In this review, we discuss the use of iPSC disease modeling in hematological diseases, where there is lack of patient sample availability and/or difficulty of engraftment to generate animal models. Furthermore, we describe the power of combining iPSC and precise gene editing to elucidate the underlying mechanism of initiation and progression of various hematological malignancies. Finally, we discuss the power of iPSC disease modeling in developing and testing novel therapies in a high throughput setting.


2021 ◽  
Vol 8 ◽  
Author(s):  
Lei Zhang ◽  
Ke Pu ◽  
Xiaojun Liu ◽  
Sarah Da Won Bae ◽  
Romario Nguyen ◽  
...  

Liver diseases are a major health concern globally, and are associated with poor survival and prognosis of patients. This creates the need for patients to accept the main alternative treatment of liver transplantation to prevent progression to end-stage liver disease. Investigation of the molecular mechanisms underpinning complex liver diseases and their pathology is an emerging goal of stem cell scope. Human induced pluripotent stem cells (hiPSCs) derived from somatic cells are a promising alternative approach to the treatment of liver disease, and a prospective model for studying complex liver diseases. Here, we review hiPSC technology of cell reprogramming and differentiation, and discuss the potential application of hiPSC-derived liver cells, such as hepatocytes and cholangiocytes, in refractory liver-disease modeling and treatment, and drug screening and toxicity testing. We also consider hiPSC safety in clinical applications, based on genomic and epigenetic alterations, tumorigenicity, and immunogenicity.


2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
Reto Eggenschwiler ◽  
Komal Loya ◽  
Malte Sgodda ◽  
Francoise André ◽  
Tobias Cantz

Direct reprogramming of somatic cells into pluripotent cells by retrovirus-mediated expression of OCT4, SOX2, KLF4, and C-MYC is a promising approach to derive disease-specific induced pluripotent stem cells (iPSCs). In this study, we focused on three murine models for metabolic liver disorders: the copper storage disorder Wilson's disease (toxic-milk mice), tyrosinemia type 1 (fumarylacetoacetate-hydrolase deficiency, FAH−/−mice), and alpha1-antitrypsin deficiency (PiZ mice). Colonies of iPSCs emerged 2-3 weeks after transduction of fibroblasts, prepared from each mouse strain, and were maintained as individual iPSC lines. RT-PCR and immunofluorescence analyses demonstrated the expression of endogenous pluripotency markers. Hepatic precursor cells could be derived from these disease-specific iPSCs applying anin vitrodifferentiation protocol and could be visualized after transduction of a lentiviral albumin-GFP reporter construct. Functional characterization of these cells allowed the recapitulation of the disease phenotype for further studies of underlying molecular mechanisms of the respective disease.


2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Guoqiang Sun ◽  
Chelsea Fu ◽  
Caroline Shen ◽  
Yanhong Shi

Stem cells have provided great hope for the treatment of a variety of human diseases. However, the molecular mechanisms underlying stem cell pluripotency, self-renewal, and differentiation remain to be unveiled. Epigenetic regulators, including histone deacetylases (HDACs), have been shown to coordinate with cell-intrinsic transcription factors and various signaling pathways to regulate stem cell pluripotency, self-renewal, and fate determination. This paper focuses on the role of HDACs in the proliferation and neuronal differentiation of neural stem cells and the application of HDAC inhibitors in reprogramming somatic cells to induced pluripotent stem cells (iPSCs). It promises to be an active area of future research.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Rui Liu ◽  
Dong Li ◽  
Fangxu Sun ◽  
Antonio Rampoldi ◽  
Joshua T. Maxwell ◽  
...  

Abstract Background Treatment-induced cardiotoxicity is a leading noncancer-related cause of acute and late onset morbidity and mortality in cancer patients on antineoplastic drugs such as melphalan—increasing clinical case reports have documented that it could induce cardiotoxicity including severe arrhythmias and heart failure. As the mechanism by which melphalan impairs cardiac cells remains poorly understood, here, we aimed to use cardiomyocytes derived from human induced pluripotent stem cells (hiPSC-CMs) to investigate the cellular and molecular mechanisms of melphalan-induced cardiotoxicity. Methods hiPSC-CMs were generated and treated with clinically relevant doses of melphalan. To characterize melphalan-induced cardiotoxicity, cell viability and apoptosis were quantified at various treatment durations. Ca2+ transient and contractility analyses were used to examine the alterations of hiPSC-CM function. Proteomic analysis, reactive oxygen species detection, and RNA-Sequencing were conducted to investigate underlying mechanisms. Results Melphalan treatment of hiPSC-CMs induced oxidative stress, caused Ca2+ handling defects and dysfunctional contractility, altered global transcriptomic and proteomic profiles, and resulted in apoptosis and cell death. The antioxidant N-acetyl-l-cysteine attenuated these genomic, cellular, and functional alterations. In addition, several other signaling pathways including the p53 and transforming growth factor-β signaling pathways were also implicated in melphalan-induced cardiotoxicity according to the proteomic and transcriptomic analyses. Conclusions Melphalan induces cardiotoxicity through the oxidative stress pathway. This study provides a unique resource of the global transcriptomic and proteomic datasets for melphalan-induced cardiotoxicity and can potentially open up new clinical mechanism-based targets to prevent and treat melphalan-induced cardiotoxicity.


Reproduction ◽  
2013 ◽  
Vol 146 (6) ◽  
pp. 569-579 ◽  
Author(s):  
Anran Fan ◽  
Kuiying Ma ◽  
Xinglan An ◽  
Yu Ding ◽  
Peipei An ◽  
...  

TET1 is implicated in maintaining the pluripotency of embryonic stem cells. However, its precise effects on induced pluripotent stem cells (iPSCs), and particularly on porcine iPSCs (piPSCs), are not well defined. To investigate the role of TET1 in the pluripotency and differentiation of piPSCs, piPSCs were induced from porcine embryonic fibroblasts by overexpression ofPOU5F1(OCT4),SOX2,KLF4, andMYC(C-MYC). siRNAs targeting toTET1were used to transiently knockdown the expression ofTET1in piPSCs. Morphological abnormalities and loss of the undifferentiated state of piPSCs were observed in the piPSCs after the downregulation ofTET1. The effects ofTET1knockdown on the expression of key stem cell factors and differentiation markers were analyzed to gain insights into the molecular mechanisms underlying the phenomenon. The results revealed that knockdown ofTET1resulted in the downregulated expression of pluripotency-related genes, such asLEFTY2,KLF2, andSOX2, and the upregulated expression of differentiation-related genes includingPITX2,HAND1,GATA6, andLEF1. However,POU5F1,MYC,KLF4, andNANOGwere actually not downregulated. Further analysis showed that the methylation levels of the promoters forPOU5F1andMYCincreased significantly afterTET1downregulation, whereas there were no obvious changes in the promoters ofSOX2,KLF4, andNANOG. The methylation of the whole genome increased, while hydroxymethylation slightly declined. Taken together, these results suggest thatTET1may play important roles in the self-renewal of piPSCs and the maintenance of their characteristics by regulating the expression of genes and the DNA methylation.


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