Molecular cytogenetics characterization of seven small supernumerary marker chromosomes derived from chromosome 19: Genotype-phenotype correlation and review of the literature.

Only a few subjects carrying supernumerary marker chromosomes derived from 19 chromosome (sSMC(19)) have been described to date and for a small portion of them the genic content has been defined at the molecular level. We present seven new different sSMCs(19) identified in eight individuals, seven of whom unrelated. The presence of the sSMC is associated with a clinical phenotype in five subjects, while the other three carriers, two of whom related, are normal. All sSMCs(19) have been characterized by means of conventional and molecular cytogenetics. We compare the sSMCs(19) carriers with a clinical phenotype to already described patients with gains (sSMCs or microduplications) of overlapping genomic regions with the aim to deepen the pathogenicity of the encountered imbalances and to assess the role of the involved genes on the phenotype. The present work supports the correlation between the gain of some chromosome 19 critical regions and specific phenotypes.

In vitro concurrent endothelial and osteogenic commitment of adipose-derived stem cells and their genomical analyses through comparative genomic hybridization array: novel strategies to increase the successful engraftment of tissue-engineered bone grafts.

In the field of tissue engineering, adult stem cells are increasingly recognized as an important tool for in vitro reconstructed tissue-engineered grafts. In the world of cell therapies, undoubtedly, mesenchymal stem cells from bone marrow or adipose tissue are the most promising progenitors for tissue engineering applications. In this setting, adipose-derived stem cells (ASCs) are generally similar to those derived from bone marrow and are most conveniently extracted from tissue removed by elective cosmetic liposuction procedures; they also show a great potential for endothelization. The aim of the present work was to investigate how the cocommitment into a vascular and bone phenotype of ASCs could be a useful tool for improving the in vitro and in vivo reconstruction of a vascularized bone graft. Human ASCs obtained from abdominoplasty procedures were loaded in a hydroxyapatite clinical-grade scaffold, codifferentiated, and tested for proliferation, cell distribution, and osteogenic and vasculogenic gene expression. The chromosomal stability of the cultures was investigated using the comparative genomic hybridization array for 3D cultures. ASC adhesion, distribution, proliferation, and gene expression not only demonstrated a full osteogenic and vasculogenic commitment in vitro and in vivo, but also showed that endothelization strongly improves their osteogenic commitment. In the end, genetic analyses confirmed that no genomical alteration in long-term in vitro culture of ASCs in 3D scaffolds occurs.

Hyaluronan and fibrin biomaterial as scaffolds for neuronal differentiation of adult stem cells derived from adipose tissue and skin.

Recently, we have described a simple protocol to obtain an enriched culture of adult stem cells organized in neurospheres from two post-natal tissues: skin and adipose tissue. Due to their possible application in neuronal tissue regeneration, here we tested two kinds of scaffold well known in tissue engineering application: hyaluronan based membranes and fibrin-glue meshes. Neurospheres from skin and adipose tissue were seeded onto two scaffold types: hyaluronan based membrane and fibrin-glue meshes. Neurospheres were then induced to acquire a glial and neuronal-like phenotype. Gene expression, morphological feature and chromosomal imbalance (kariotype) were analyzed and compared. Adipose and skin derived neurospheres are able to grow well and to differentiate into glial/neuron cells without any chromosomal imbalance in both scaffolds. Adult cells are able to express typical cell surface markers such as S100; GFAP; nestin; ßIII tubulin; CNPase. In summary, we have demonstrated that neurospheres isolated from skin and adipose tissues are able to differentiate in glial/neuron-like cells, without any chromosomal imbalance in two scaffold types, useful for tissue engineering application: hyaluronan based membrane and fibrin-glue meshes.

Silver-Russell syndrome and Beckwith-Wiedemann syndrome phenotypes associated with 11p duplication in a single family.

Genomic imprinting is an epigenetic phenomenon resulting in differential expression of maternal and paternal alleles of a subset of genes. In the mouse, mutation of imprinted genes often results in contrasting phenotypes, depending on parental origin. The overgrowth-associated Beckwith-Wiedemann syndrome (BWS) and the growth restriction-associated Silver-Russell syndrome (SRS) have been linked with a variety of epigenetic and genetic defects affecting a cluster of imprinted genes at chromosome 11p15.5. Paternally derived and maternally derived 11p15.5 duplications represent infrequent findings in BWS and SRS, respectively. Here, we report a case in which a 6.5 Mb duplication of 11p15.4-pter resulted in SRS and BWS phenotypes in a child and her mother, respectively. Molecular analyses demonstrated that the duplication involved the maternal chromosome 11p15 in the child and the paternal chromosome 11p15 in the mother. This observation provides a direct demonstration that SRS and BWS represent specular images, both at the clinical and molecular levels.