Plasticity of human adipose tissue-derived stem cells (hADSCs) - potential for therapeutic use

Supervisor: Dr Patrizia Ferretti

Aims:
The aim of the project is to better understand the basis of hADSC (adipose tissue-derived stem cell) plasticity and establish whether it can be harnessed to bioengineer autologous complex tissues for establishing human models of disease and for repair/reconstruction of abnormal structures in children with congenital abnormalities.

Background:
We have evidence that paediatric adipose tissue-derived stem cells (hADSCs) not only have a significant differentiation potential along mesenchymal lineages and could provide a valuable source of stem cells for autologous cell therapy, but they can also undergo differentiation along neuroectodermal lineages. This is shown by morphological changes and up-regulation of neuronal/glial markers and tight junction markers, that are consistent with conversion to the neural and epithelial lineage, respectively (Guasti et al. 2012; New et al. in preparation). Clonal hADSC lines already generated will be used to study ADSC differentiation potential, and the mechanisms controlling it. Focus will be on the role of a family of calcium-dependent enzymes (PADs), that we have recently found to be regulated during chondrogenic differentiation of both hADSCs and chondrobalsts, as their dysregulation may be associated with reumathoid arthritis. A better understanding of the population(s) present in hADSC cultures, of their full differentiation potential, and of the mechanisms controlling it will underpin their use both for disease modelling and for bio-engineering a variety of tissues for autologous cell therapies aimed at reconstruction of abnormal structures in children with congenital birth defects.

Objectives:

  • To establish whether hADSCs represent a homogeneous cell population or contain progenitors for different lineages using clonal lines already available and new ones that will be established by the student.
  • To further characterize the phenotype and behaviour of hADSC induced to differentiate along mesenchymal and neuroectodermal lineages in 3-dimensional scaffolds to better mimic the in vivo situation and following grafting in chick embryos.
  • To assess early changes in hADSC phenotype upon induction of skeletal differentiation and in particular establish the role of members of the PAD enzyme family.

Altogether, the student will gain extensive theoretical knowledge and practical experience in a broad range of techniques including cell culture, stem cell biology, cell analysis (e.g. time-lapse microscopy, FACS) protein and RNA analysis (e.g. immunocytochemistry, q-PCR), enzymatic assays, manipulation of gene expression (siRNA), detection of apoptotic cells, imaging techniques (e.g. confocal microscopy).

References:
1) Guasti L, Prasongchean W, Kleftorious G, Mukherjee S, Thrasher AJ, Bulstrode NW, Ferretti P. High plasticity of paediatric adipose tissue-derived stem cells: too much for selective skeletogenic differentiation? . Stem Cells Trans Med. 2012;1:384-395.
2) Prasongchean W, Ferretti P. Autologous stem cells for personalised medicine. New biotechnology. 2012;29:641-645
3) Prasongchean W, Bagni M, Calzarossa C, De Coppi P and Ferretti P * (2011). Amniotic fluid stem cells increase embryo survival following injury. Stem Cells Dev. 21:675-88.
4) Lange S, Gögel S, Leung KY, Nicholas AP, Causey CP, Thompson PR, Greene NDE and Ferretti P* (2011). Protein deiminases: New players in the developmentally regulated loss of neural regenerative ability. Dev Biol 355:205-214.
5) Sottocornola R, Vives V, Royer C, Zhong S, Ratnayaka I, Cheung A, Gaston-Massuet C, Ferretti P, Molnár Z and Lu X (2010). ASPP2: a new player in the maintenance of neural progenitor polarity and proliferation during CNS development. Dev Cell 19, 126-37