Reprogramming of Human Peripheral Blood Mononuclear Cell (PBMC) from a patient suffering of a Werner syndrome resulting in iPSC line (REGUi003-A) maintaining a short telomere length

Generation of patient-specific induced pluripotent stem cell lines with Type 2 Long QT Syndrome and the KCNH2 c.379C > T pathogenic variant

Type 2 Long QT Syndrome (LQT2) is a rare genetic heart rhythm disorder causing life-threatening arrhythmias. We derived induced pluripotent stem cell (iPSC) lines from two patients with LQT2, aged 18 and 6, both carrying a heterozygous missense mutation on the 3rd and 11th exons of KCNH2. The iPSC lines exhibited normal genomes, expressed pluripotent markers, and differentiated into trilineage embryonic layers. These patient-specific iPSC lines provide a valuable model to study the molecular and functional impact of the hERG channel gene mutation in LQT2 and to develop personalized therapeutic approaches for this syndrome.

Generation of catecholaminergic polymorphic ventricular tachycardia patient-specific induced pluripotent stem cell line

Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT) is a genetic disorder characterized by ventricular tachycardia, that can cause the heart to stop beating leading to death. The prevalence is 1/10.000 and in approximately 60% of cases, the syndrome can be due to a mutation of the cardiac ryanodine receptor gene (RyR2). We derived an induced pluripotent stem cell (iPSC) line from an 11-year-old patient blood-cells, carrying a heterozygous missense mutation on the 8th exon of the RyR2 N-terminal part. This reprogramed CPVT line displayed normal karyotype, expressed pluripotent markers and had a capacity to differentiate in trilineage embryonic layers.

Current status and future prospects of patient-derived induced pluripotent stem cells

Induced pluripotent stem cells (iPSCs) are produced from adult somatic cells through reprogramming, which behave like embryonic stem cells (ESCs) but avoiding the controversial ethical issues from destruction of embryos. Since the first discovery in 2006 of four factors that are essential for maintaining the basic characteristics of ESC, global researches have rapidly improved the techniques for generating iPSCs. In this paper, we review new insights into patient-specific iPSC and summarize selected "disease-in-a-dish" examples that model the genetic and epigenetic variations of human diseases. Although more researches need to be done, studies have increasingly focused on the potential utility of iPSCs. The usability of iPSC technology is changing the fields of disease modeling and precision treatment. Aside from its potential use in regenerative cellular therapy for degenerative diseases, iPSC offers a range of new opportunities for the study of genetic human disorders, particularly, rare diseases. We believe that this rapidly moving field promises many more developments that will benefit modern medicine.

An Overview on Promising Somatic Cell Sources Utilized for the Efficient Generation of Induced Pluripotent Stem Cells

Human induced Pluripotent Stem Cells (iPSCs) have enormous potential in understanding developmental biology, disease modeling, drug discovery, and regenerative medicine. The initial human iPSC studies used fibroblasts as a starting cell source to reprogram them; however, it has been identified to be a less appealing somatic cell source by numerous studies due to various reasons. One of the important criteria to achieve efficient reprogramming is determining an appropriate starting somatic cell type to induce pluripotency since the cellular source has a major influence on the reprogramming efficiency, kinetics, and quality of iPSCs. Therefore, numerous groups have explored various somatic cell sources to identify the promising sources for reprogramming into iPSCs with different reprogramming factor combinations. This review provides an overview of promising easily accessible somatic cell sources isolated in non-invasive or minimally invasive manner such as keratinocytes, urine cells, and peripheral blood mononuclear cells used for the generation of human iPSCs derived from healthy and diseased subjects. Notably, iPSCs generated from one of these cell types derived from the patient will offer ethical and clinical advantages. In addition, these promising somatic cell sources have the potential to efficiently generate bona fide iPSCs with improved reprogramming efficiency and faster kinetics. This knowledge will help in establishing strategies for safe and efficient reprogramming and the generation of patient-specific iPSCs from these cell types.

Reprogramming: Emerging Strategies to Rejuvenate Aging Cells and Tissues

Aging is associated with a progressive and functional decline of all tissues and a striking increase in many "age-related diseases". Although aging has long been considered an inevitable process, strategies to delay and potentially even reverse the aging process have recently been developed. Here, we review emerging rejuvenation strategies that are based on reprogramming toward pluripotency. Some of these approaches may eventually lead to medical applications to improve healthspan and longevity.

Generation of three Duchenne Muscular Dystrophy patient-specific induced pluripotent stem cell lines DMD_YoTaz_PhyMedEXp, DMD_RaPer_PhyMedEXp, DMD_OuMen_PhyMedEXp (INSRMi008-A, INSRMi009-A and INSRMi010-A)

Duchenne Muscular Dystrophy (DMD) is a X-linked degenerative pathology with a prevalence of 1/3600-6000 boys due to the absence of functional dystrophin in muscles. This muscular disease leads to skeletal muscle damages, respiratory failure and in the later stages dilated cardiomyopathy (DCM) leading to heart failure. We generated iPSC lines from three different DMD patients carrying respectively deletions of exons 1, 52 and 55 in the dystrophin gene. The reprogrammed iPSC lines showed expression of pluripotent markers, capacity to differentiate in trilineage embryonic layers and a normal karyotype.

iPSC reprogramming of fibroblasts from a patient with a Rothmund-Thomson syndrome RTS

Rothmund-Thomson Syndrome (RTS) is a rare autosomal recessive disease that manifests several clinical features of accelerated aging. These findings include atrophic skin and pigment changes, alopecia, osteopenia, cataracts, and an increased incidence of cancer for patients. Mutations in RECQL4 gene are responsible for cases of RTS. RECQL4 belongs to the RECQ DNA helicase family which has been shown to participate in many aspects of DNA metabolism. To be able to study the cellular defects related to the pathology, we derived an induced pluripotent cell line from RTS patient fibroblasts, with the ability to re-differentiate into the three embryonic germ layers.

RECQ DNA Helicases and Osteosarcoma

The RECQ family of DNA helicases is a conserved group of enzymes that plays an important role in maintaining genomic stability. Humans possess five RECQ helicase genes, and mutations in three of them - BLM, WRN, and RECQL4 - are associated with the genetic disorders Bloom syndrome, Werner syndrome, and Rothmund-Thomson syndrome (RTS), respectively. These syndromes share overlapping clinical features, and importantly they are all associated with an increased risk of cancer. Patients with RTS have the highest specific risk of developing osteosarcoma compared to all other cancer predisposition syndromes; therefore, RTS serves as a relevant model to study the pathogenesis and molecular genetics of osteosarcoma. The "tumor suppressor" function of the RECQ helicases continues to be an area of active investigation. This chapter will focus primarily on the known cellular functions of RECQL4 and how these may relate to tumorigenesis, as well as ongoing efforts to understand RECQL4's functions in vivo using animal models. Understanding the RECQ pathways will provide insight into avenues for novel cancer therapies in the future.

iPSC line derived from a Bloom syndrome patient retains an increased disease-specific sister-chromatid exchange activity

Bloom syndrome is characterized by severe pre- and postnatal growth deficiency, immune abnormalities, sensitivity to sunlight, insulin resistance, and a high risk for many cancers that occur at an early age. The diagnosis is established on characteristic clinical features and/or presence of biallelic pathogenic variants in the BLM gene. An increased frequency of sister-chromatid exchanges is also observed and can be useful to diagnose BS patients with weak or no clinical features. For the first time, we derived an induced pluripotent cell line from a Bloom syndrome patient retaining the specific sister-chromatid exchange feature as a unique tool to model the pathology.