Irina Kerkis

Establishment of new murine embryonic stem cell lines for the generation of mouse models of human genetic diseases

Embryonic stem cells are totipotent cells derived from the inner cell mass of blastocysts. Recently, the development of appropriate culture conditions for the differentiation of these cells into specific cell types has permitted their use as potential therapeutic agents for several diseases. In addition, manipulation of their genome in vitro allows the creation of animal models of human genetic diseases and for the study of gene function in vivo. We report the establishment of new lines of murine embryonic stem cells from preimplantation stage embryos of 129/Sv mice. Most of these cells had a normal karyotype and an XY sex chromosome composition. The pluripotent properties of the cell lines obtained were analyzed on the basis of their alkaline phosphatase activity and their capacity to form complex embryoid bodies with rhythmically contracting cardiomyocytes. Two lines, USP-1 and USP-3, with the best in vitro characteristics of pluripotency were used in chimera-generating experiments. The capacity to contribute to the germ line was demonstrated by the USP-1 cell line. This cell line is currently being used to generate mouse models of human diseases.

Chromosome abnormalities in two patients with features of autosomal dominant Robinow syndrome

How to cite this article: Mazzeu JF, Krepischi-Santos AC, Rosenberg C, Szuhai K, Knijnenburg J,Weiss JMM, Kerkis I, Mustacchi Z, Colin G, Mombach R, Pavanello RM, Otto PA,Vianna-Morgante AM. 2007. Chromosome abnormalities in two patients with features ofautosomal dominant Robinow syndrome. Am J Med Genet Part A 143A:1790–1795.

Generation of Induced Pluripotent Stem Cells from Dental Pulp Somatic Cells

During early development, human dental pulp is originated from neural crest, which is a transient embryonic structure (Fig. 1). According to current knowledge, neural crest stem cells (NCSCs) have the capacity to self-renewal and display a developmental potential almost the same as embryonic stem (ES) cells (Kerkis and Caplan, 2012). These postmigratory NCSCs generate all craniofacial bones, the majority of the peripheral nervous system cells and tissues, as well as several non-neural cell types, such as smooth muscle cells of the cardiovascular system, pigment cells in the skin, cartilage, connective tissue, corneal epithelium and dental pulp among them. Although postmigratory, postnatal NCSCs are of restricted developmental potential they maintain functional characteristics resembling their embryonic counterparts and an ability to differentiate into a broad spectrum of cell types (Le Douarin et al., 2004, 2007, 2008; Dupin et al., 2007; Le Douarin & Dupin, 2003, 2012).

Actual Achievements on Germ Cells and Gametes Derived from Pluripotent Stem Cells

In mammals, the specification of GC begins during cleavage; GC first appears near the gut and further migrates to the developing gonads. The lineage of GC is called germ line. They are unique cells, which undergo cell division of two types, mitosis and meiosis, in contrast to somatic cells of mammal’s body, which only divide by mitosis. Accordingly to Fig. 2 following further differentiation GC can be transformed into mature gamete, either eggs or sperm (Adams & McLaren, 2002). There is growing evidence for effects of environmental

Pluripotent Stem Cells as an In Vitro Model of Neuronal Differentiation

Irina Kerkis1, Mirian A. F. Hayashi2, Nelson F. Lizier1, Antonio C. Cassola3, Lygia V. Pereira4 and Alexandre Kerkis5 1Laboratory of Genetics, Butantan Institute and Department of Morphology and Genetics, Federal University of Sao Paulo, 2Departament of Pharmacology, Federal University of Sao Paulo, 3Department of Physiology and Biophysics, University of Sao Paulo, 4Institute of Biosciences, University of Sao Paulo, 5Celltrovet (Genetica Aplicada), Ltda. Brazil

Pluripotent Stem Cells to Model and Treat Huntington’s Disease

Stem cell therapies hold considerable promise for the treatment of neurodegenerative diseases. Pluripotent stem cells (PSCs) have been of particular clinical interest because of their ability to generate neuronal cells and to be used in animal models of neurodegenerative disease as well as for testing new drugs. Several PSCs isolated from humans and animals that carry the genotype of Huntington’s disease (HD) have been used in aforementioned studies. HD-PSCs obtained can produce in vitro neural progenitor cells (NPCs). These NPCs applied in HD models show several advantages: they engraft into the brain in animal models and differentiate into neuronal cells, thus promoting behavioral recovery and motor impairment. Although progress has been made using PSCs, additional tests should be done to overcome several limitations as, for example, tumorigenicity, before their clinical application. We focus this chapter on current knowledge regarding HD-PSC lines and their helpfulness as an in vitro model for basic research. Next, we discuss the advances of disease-free PSCs in preclinical HD models aiming to their potential application in patients. Additionally, we discuss their potential use as a test system for anti-HD drug screening by the pharmaceutical industry, especially considering HD patients’ welfare.

Induced Pluripotent Stem Cells Derived from Dental Stem Cells: A New Tool for Cellular Therapy

Induced pluripotent stem cells (iPSCs) are a type of experimentally produced pluripotent stem cell (PSC), which share similar features with embryonic stem cells (ES) isolated directly from early embryos. Shinya Yamanaka’s lab in Kyoto, Japan was the first to develop iPSCs in 2006 by the introduction of four genes that encode transcription factors of PSC into mouse embryonic fibroblasts—a process known as “reprogramming”. Later on, different animal and human fetal or adult somatic cell types have been converted into iPSCs using this technology, demonstrating similarities and slight differences between iPSCs lines, which are known to depend on the origin of the cells used in reprogramming. The present chapter will provide an overview of iPSCs derived from dental stem cells (DSCs), such as stem cells isolated from apical papilla (SCAPs), stem cells from exfoliated deciduous teeth (SHEDS), from pulp of third molars and adult permanent teeth (DPSCs). We will discuss the origin of the cells used for reprogramming, factors which may favor or hinter the reprogramming process, methods and efficiency of cell reprogramming; the differentiation ability of iPSCs derived from DSCs; their safety, tolerance by the host and regenerative potential in preclinical models, as well as the use of these cells in toxicological studies, disease modeling and drug discovery. The possible use of iPSCs obtained from DSCs as a new tool for regenerative therapy will also be shortly discussed.

Dental Stem Cells: Risk and Responsibilities

In early embryo development, the tooth tissues are originated from the neural crest anatomical site. Neural crest stem cells are considered embryonic-like stem cells, which are maintained under the control of Hox genes. Moreover, they are clonogenic cells and are able to differentiate into various cell types, such as odontoblasts, osteoblasts, chondrocytes, neurons, melanocytes, and the muscles. Following the migration of neural crest stem cells during fetal development, the oral epithelium- and cranial crest-derived mesenchymal cells arise, which next form the dental follicle and dental pulp.