The Wolfe PGD-Stem Cell Research Lab

Research & Development

About the Laboratory



The Wolfe PGD-Stem Cell Lab under the direction of Prof. Dalit Ben-Yosef focuses on studying issues related to early embryonic and developmental processes, genetic disorders and different aspects of cell therapy using our unique collection of PGD-derived human embryonic stem cells (hESCs).


We derive hESCs directly from affected embryos, which are obtained as a by-product of the preimplantation genetic diagnosis (PGD) procedure. PGD is performed for couples at high risk of transmitting a genetic defect and who wish to ensure the birth of a healthy child. It requires in vitro fertilization (IVF), which makes the pre-implantation embryos available for biopsy and single-cell molecular analysis. Following IVF-PGD, embryos diagnosed as being disease-free are transferred into the uterus for implantation, whereas the affected embryos that would be otherwise discarded are used to establish hESC lines that carry the naturally inherited mutations. This setup provides the benefit of efficient coordination between the generously donated affected embryos and the stem cell lab that focuses on researching these very unique samples. By means of these capabilities, we have already established >50 mutant hESC lines associated with 18 different inherited disorders.
 


 

These lines make it possible for us to study the molecular and pathophysiological mechanisms underlying the genetic disease of which they were diagnosed. In addition, the fact that we have a huge collection of hESC lines derived under the same conditions enable us to perform different studies on the pluripotent, genetic and epigenetic properties of these cells.

Current Research

1. Study of Fragile X syndrome (FXS)


Fragile X syndrome is the most common form of inherited intellectual disability caused by inherited triplet repeat expansion in the gene FMR1. To study the molecular and functional effect of this disease we use a panel of disease carrying hESC lines and differentiate them into electrically functional neurons. We showed that: A. the CGG expansion alone is not sufficient for FMR1 gene silencing (Eiges et al., and Ben-Yosef, Cell Stem Cell 2007). B. Although FXS hESC develop into neurons they are less efficient in doing so. Furthermore, the resulting neurons demonstrate significant maturation deficits (Telias et al., Developmental Biology 2013; Telias et al., Stem Cells and Development 2015a; Telias et al., The Journal of Neuroscience 2015b). Currently we are working on further elucidating the molecular pathways that are affected by FMR1 mutation, as well as studying the behavior of FXS-hESC derived neuronal networks. This will enable the identification of new therapeutic targets for FXS, whereupon our steady production of human FXS neurons in-vitro can also be used as a reliable drug screening platform.


2. Study of malignant transformation using adenomatous polyposis coli (APC)-mutated hESCs


Colorectal cancer (CRC) is one of the leading causes of morbidity and mortality associated with malignant pathologies. Most cases of hereditary and sporadic CRCs are triggered as a result of mutations in the APC gene. We have generated several hESC lines from embryos donated by familial adenomatous polyposis (FAP) patients who carry the germline nutation in the APC gene (Yedid et al., 2016). All these FAP patients will develop CRC by middle-age. We use these FAP-hESC lines to study the conditions and the molecular mechanisms leading to malignant transformation.


3. Understanding implantation failure using hESCs carrying chromosomal translocations


Implantation of an embryo in the uterus is a complex process that requires a functionally normal blastocyst. It occurs only when the endometrium is receptive. Implantation failure is one of the main causes of infertility, and carriers of chromosomal translocations bear a high risk for its occurrence. We have derived several hESC lines from embryos harboring different chromosomal translocations. We are using these translocated hESC lines for studying trophoblast differentiation and the mechanisms underlying early stages of implantation (Shpitz et al., Molecular Human Reproduction 2015; Shpitz et al., Journal of Assisted Reproduction and Genetics 2016).
4. Genomic and phenotypic analysis of naïve and primed hESC lines to ensure their safety for cell therapy


hESCs have tremendous potential as sources of material for cell transplantation therapy. Using a combination of cytogenetic and molecular analysis approaches, including high-resolution SNP genotyping, karyotyping, and STR analysis, we compared genetic aberrations in the hESCs to those in the DNA obtained from the parents who donated the embryos. This strategy enables us to identify, for the first time, de-novo copy number variants acquired during derivation, to define the stages at which these events occurs, and to trace the origin of the affected alleles (Ben-Yosef et al., Cell Reports 2013). Genetic instability is well known to characterize cancer cells and can impair their use as a therapeutic tool. In 2013, in collaboration with Dr. Hanna’s group we derived naïve hESC lines directly from blastocysts (Gafni et al., Nature 2013). The naïve state representing an earlier, less committed stage of development than the primed state. We now compare genomic stability and cellular phenotype of naïve and primed hESCs, in order to distinguish between genetic changes that do not have clinically significant effects and those that confer malignant properties to the cells.

List of Lis- hESC lines derived in our lab

 

hESC line

Primed

Fragile X

Lis01_HEFX1

Primed

Fragile X

Lis02_FXS_2

Primed

Fragile X

Lis03_FXS_4

Primed

Saethre-Chotzen syndrome

Lis04_Twist

Primed

Translocation (11;22)

Lis05_t(11,22)

Primed

Gaucher 

Lis06_Gaucher_1

Primed

Androgen insensitivity

Lis07_AIS_1

Primed

Androgen insensitivity

Lis08_AIS_2

Primed

Torsion dystonia

Lis09_DYS_1

Primed

Duchenne muscular dystrophy

Lis10_DMD_1

Primed

Duchenne muscular dystrophy

Lis11_DMD_2

Primed

Myotonic dystrophy

Lis12_DM_1

Primed

Alport

Lis13_ Alport_2

Primed

Alport

Lis14_ Alport_3

Primed

Translocation (1;12)

Lis15_t(1;12)

Primed

Non syndromic deafness

Lis17_Connexin_1

Primed

Non syndromic deafness

Lis18_Connexin_2

Primed

Myotonic dystrophy

Lis19_DM_2

Primed

Duchenne muscular dystrophy

Lis20_DMD_3

Primed

Noonan

Lis21_Noonan_1

Primed

Duchenne muscular dystrophy

Lis22_DMD_4

Primed

Duchenne muscular dystrophy

Lis23_DMD_5

Primed

Fragile X

Lis24_FXS_5

Primed

Familial Adenomatous Polyposis

Lis25_FAP_1 

Primed

Fragile X

Lis26_FXS_6

Primed

translocation (Y;14)

Lis27_t(Y;14)_1

Primed

translocation (Y;14)

Lis28_t(Y;14)_2

Primed

Fragile X

Lis29_FXS_7

Primed

Familial Adenomatous Polyposis

Lis30_FAP_2

Primed

Myotonic dystrophy

Lis31_DM_3

Primed

Myotonic dystrophy

Lis32_DM_4

Primed

Norrie

Lis33_Norrie

Primed

Familial Adenomatous Polyposis

Lis34_FAP_3

Primed

X-linked hydrocephaly

Lis35_Hydrocephaly

Naïve

WT

Lis36

Primed

Fragile X

Lis37_FXS_10

Naïve

Fragile X

Lis38_FXS7_N

Naïve

Fragile X

Lis39_FXS8_N

Naïve

WT

Lis40_N

Naïve

Leukoencephalopathy with thalamus and brainstem involvement and high lactate

Lis 41_LTBL_N

Naïve

Neurofibromatosis type I

Lis 42_NF1_1_N

Naïve

Non Syndromic deafness

Lis 43_connexin_3_N

Naïve

Ichthyosis

Lis 45_Ichthyosis_1_N

Naïve

Ichthyosis

Lis 46_Ichthyosis_2_N

Naïve

Neurofibromatosis type I

Lis47_NF1_2_N

Naïve

Duchenne muscular dystrophy

Lis 48_DMD_6_N

Naïve

Hydrocephaly

Lis 49_hydrocephaly_N

Naïve

Hydrocephaly

Lis 50_hydrocephaly_N

Naïve

Fragile X

Lis 51_FXS_9_N

Naïve

WT

Lis1

Naïve

WT

Lis2

Primed

Fragile X

Lis 52_FXS_11

Primed

Fragile X

Lis 53_FXS_12

Publications

For a listing of recent publications, refer to PubMed, a service provided by the National Library of Medicine 

Collaborations

 

·         Ayelet Erez, Department of Biological Regulation, Weizmann Institute of Science.

·         Inna Slutsky, Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University.

·         Jacob Hanna, Department of Molecular Genetics, Weizmann Institute of Science.

·         Louise Laurent, Department of Reproductive Medicine, University of California, San Diego, USA.

·         Menahem Segal, Department of Neurobiology, Weizmann Institute of Science.

·         Oren Ram, Department of Biochemistry, The Alexander Silberman Institute of Life Sciences. The Hebrew University of Jerusalem.

·         Rachel Eiges, Stem Cell Research Laboratory, Shaare Zedek Medical Center.

           Rina Arbesfeld, Department of Anatomy and Anthropology, Faculty of Medicine,
           Tel  Aviv University
 

Team

Scientific Director – Dalit Ben-Yosef PhD

Stem Cell Lab
Yoav Mayshar PhD, Senior Scientist (link to CV)
Hadar Amir MD/PhD, Gynecologist/Investigator (link to CV)
Lital Ovadia, PhD student
Liron Kuznitsov-Yanovsky, PhD student
Chen Dekel, PhD student
Livia Presler, PhD student


 

Undergrads
Dafna Haran
David Shaul

 

Former Students
Michael Telias PhD
Nofar Yedid MSc
Alina Shpiz MSc
Eran Parnasa
Reut Weissgross
Neta Harari
Sandy Bornstein, Medical student

 

Contact information

Phone: + 972-3-6925733

Email: dalitb@tlvmc.gov.il


Location

Sourasky building, floor 3, wing C

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