Gain of 20q11.21 in Human Pluripotent Stem Cells Impairs TGF-ß-Dependent Neuroectodermal Commitment.

Gain of 20q11.21 is one of the most common recurrent genomic aberrations in human pluripotent stem cells. Although it is known that overexpression of the antiapoptotic gene Bcl-xL confers a survival advantage to the abnormal cells, their differentiation capacity has not been fully investigated. RNA sequencing of mutant and control hESC lines, and a line transgenically overexpressing Bcl-xL, shows that overexpression of Bcl-xL is sufficient to cause most transcriptional changes induced by the gain of 20q11.21. Moreover, the differentially expressed genes in mutant and Bcl-xL overexpressing lines are enriched for genes involved in TGF-ß- and SMAD-mediated signaling, and neuron differentiation. Finally, we show that this altered signaling has a dramatic negative effect on neuroectodermal differentiation, while the cells maintain their ability to differentiate to mesendoderm derivatives. These findings stress the importance of thorough genetic testing of the lines before their use in research or the clinic.

Stem cells in reproductive medicine: ready for the patient?

STUDY QUESTION: Are there effective and clinically validated stem cell-based therapies for reproductive diseases? SUMMARY ANSWER: At the moment, clinically validated stem cell treatments for reproductive diseases and alterations are not available. WHAT IS KNOWN ALREADY: Research in stem cells and regenerative medicine is growing in scope, and its translation to the clinic is heralded by the recent initiation of controlled clinical trials with pluripotent derived cells. Unfortunately, stem cell 'treatments' are currently offered to patients outside of the controlled framework of scientifically sound research and regulated clinical trials. Both physicians and patients in reproductive medicine are often unsure about stem cells therapeutic options. STUDY DESIGN, SIZE, DURATION: An international working group was assembled to review critically the available scientific literature in both the human species and animal models. PARTICIPANTS/MATERIALS, SETTING, METHODS: This review includes work published in English until December 2014, and available through Pubmed. MAIN RESULTS AND THE ROLE OF CHANCE: A few areas of research in stem cell and reproductive medicine were identified: in vitro gamete production, endometrial regeneration, erectile dysfunction amelioration, vaginal reconstruction. The stem cells studied range from pluripotent (embryonic stem cells and induced pluripotent stem cells) to monopotent stem cells, such as spermatogonial stem cells or mesenchymal stem cells. The vast majority of studies have been carried out in animal models, with data that are preliminary at best. LIMITATIONS, REASONS FOR CAUTION: This review was not conducted in a systematic fashion, and reports in publications not indexed in Pubmed were not analyzed. WIDER IMPLICATIONS OF THE FINDINGS: A much broader clinical knowledge will have to be acquired before translation to the clinic of stem cell therapies in reproductive medicine; patients and physicians should be wary of unfounded claims of improvement of existing medical conditions; at the moment, effective stem cell treatment for reproductive diseases and alterations is not available. STUDY FUNDING/COMPETING INTERESTS: None. TRIAL REGISTRATION NUMBER: NA.

Overcritical rotation of a trapped Bose-Einstein condensate.

The rotational motion of an interacting Bose-Einstein condensate confined by a harmonic trap is investigated by solving the hydrodynamic equations of superfluids, with the irrotationality constraint for the velocity field. We point out the occurrence of an overcritical branch where the system can rotate with angular velocity larger than the oscillator frequencies. We show that in the case of isotropic trapping the system exhibits a bifurcation from an axisymmetric to a triaxial configuration, as a consequence of the interatomic forces. The dynamical stability of the rotational motion with respect to the dipole and quadrupole oscillations is explicitly discussed.

Chorionic DNA analysis for the prenatal diagnosis of familial hypercholesterolaemia.

Prenatal diagnosis for familial hypercholesterolaemia (FH) was performed by using restriction fragment length polymorphisms (RFLPs) of the LDL receptor gene on chorionic villi DNA taken during the 10th week of pregnancy. Both parents were FH heterozygotes and had previously had a healthy son and an FH homozygous son. Two RFLPs were informative in this family and revealed that the fetus was unaffected by FH. At birth the child was found to have an LDL cholesterol level of 30 mg/dl and a normal LDL receptor activity in cultured umbilical cord fibroblasts. RFLP analysis on chorionic villi DNA is highly recommended for all heterozygous FH couples in whom the LDL receptor gene mutation/s is/are still to be characterized.

Alternative splicing of mutant LDL-receptor mRNA in an Italian patient with familial hypercholesterolemia due to a partial deletion of LDL-receptor gene (FHPotenza).

An analysis of LDL-receptor gene was performed on an Italian patient with heterozygous familial hypercholesterolemia. Restriction enzyme analysis showed that the proband was heterozygous for a deletion of 4.5 kb spanning the 5' end of exon 13 (45 nucleotide residues) to intron 15. Amplification of genomic DNA, using polymerase chain reaction (PCR), followed by direct sequencing, showed that this deletion was identical to the one reported by Lehrman et al. (1986. Proc. Natl. Acad. Sci. 83: 3679-3683). As only the normal LDL-receptor mRNA was detectable in proband fibroblasts by Northern blot, we used reverse transcription-PCR to amplify the mutant mRNA using primers complementary to exon 6 (sense) and exon 18 (antisense). The amplification of control cDNA resulted in a single fragment of 1725 nucleotides containing the normal sequence. The amplification of cDNA from the proband produced the 1725-nucleotide fragment (as in the control) and three additional fragments (F1, F2, and F3) of smaller size. The direct sequence showed that in the F1 fragment exon 12 was joined to exon 16; in the F2 fragment exon 12 was joined to exon 17; and in the F3 fragment exon 11 was joined to exon 16. Thus, the deletion-bearing allele generated three mRNAs, two of which resulted from alternative splicings leading to the skipping of exons 16 and 12, respectively. It is expected that the translation of these mutant mRNAs will generate three aberrant proteins, the synthesis of which should be negligible in view of the very low content of the corresponding mRNAs.