The role of nuclear architectural proteins in the differentiation of adult stem cells of the hair follicle

Lead Research Organisation: Durham University
Department Name: Biological and Biomedical Sciences

Abstract

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Technical Summary

Hutchinson-Gilford progeria syndrome (HGPS) is a rare genetic disease, reminiscent of accelerated ageing. Diagnostic features of the syndrome cover growth retardation, osteoporosis, loss of subcutaneous fat, skleroderma, arteriosclerosis, muscle atrophy and alopecia. Classical cases of HGPS bear a single-base substitution in the LMNA gene, encoding two protein products, lamin A and lamin C, which are the main components of the inner nuclear lamina. Based upon work that I have performed with Professor Chris Hutchison, we have proposed that some of the symptoms of HGPS arise through failure of adult stem cells to support tissue regeneration, through impairment of transcription repressor pathways. Moreover, recent data suggests that some features of HGPS are representative of normal ageing which may also occur through failure of adult stem cells to support tissue regeneration.
One of the common features of premature aging syndrome is severe alopecia, which suggests the possibility of impaired hair growth cycle. At present almost nothing is known about the cellular mechanisms that support hair development and regeneration. It seems likely that lamin A is an important determinant of the process, since we have observed dramatic changes in lamin A expression patterns in adult stem cells upon the hair follicle formation.
Hair regeneration will be used as a model to investigate the role of lamin A in adult stem cell differentiation. Adult dermal stem cells isolated from rat hair follicles, when co-cultured with epithelial cells induce hair differentiation in vitro. Each cell type can also be cultured separately so they can be manipulated independently with respect to lamin expression. Stable RNAi knock down cell lines or cells lines expressing dominant negative lamin mutants will be generated and analysed for proliferative behaviour, ability to form aggregates and induction of hair development or differentiation into adipocytes. The work would also concentrate on the identification of transcription factors and signalling pathways influenced by lamin A or it‘s binding partners. Two lamin A downstream target signalling pathways would be analysed, namely retinoblastoma protein and beta-catenin/wnt, because both are strongly associated with hair follicle regeneration and lamin A function. These studies are important, because they will provide a platform for understanding why adult stem cells might fail to support tissue regeneration in both the disease model and during normal ageing.
 
Title Dermal papilla cell lines expressing progerin 
Description Rat dermal papilla cell lines stably transfected in Tet-On Tet-Off system with dominant negative form of human lamin A (progerin) associated with the progeroid syndrome. The cells analysed for proliferative behaviour, ability to form aggregates and induction of hair development and differentiation into adipocytes. 
Type Of Material Cell line 
Provided To Others? No  
Impact Hutchinson-Gilford progeria syndrome (HGPS) is a rare genetic disorder, reminiscent of accelerated ageing and associated with growth retardation, osteoporosis, loss of subcutaneous fat, scleroderma, arteriosclerosis and muscle atrophy. Some of the symptoms of HGPS arise through failure of adult stem cells to support tissue regeneration. One of the common features of HGPS is alopecia, suggesting possibility of impaired hair growth cycle and adult stem differentiation. The generated dermal papilla cell lines serve as a unique model to investigate the role of lamin A in these processes. 
 
Title Human dermal papilla microarray database 
Description Explants of dermal papilla were isolated from human hair follicles and alternatively the cells maintained through serial passages, from passage 1 to 7, until reaching a senescent state. In addition to the growth media, different cellular populations have been also stimulated with the adipogenic differentiation media. This approach has revealed that the loss of hair-inductive markers was closely associated with the dramatic changes in a stem cell function and a switch from the adipogenic to the osteogenic program. Global assessment of transcriptional changes in the different cellular populations were performed using genome wide Affymetrix microarray analysis. 
Type Of Material Database/Collection of Data/Biological Samples 
Year Produced 2008 
Provided To Others? Yes  
Impact Identification of the novel biomarkers associated with the inductive capacities of the mesenchyme as well as stem cell function that can promote adipogenic differentiation. The biomarkers can be clustered in the groups comprised of regulators of development and morphogenesis, regulators of transcription, cellular communication and extra-cellular signalling, inflammatory response and primary metabolic processes and should reveal how the dual function of the mesenchyme can facilitate control of organ regeneration. 
 
Description Regenerative capacities of the hair follicle mesenchyme 
Organisation Columbia University
Country United States 
Sector Academic/University 
PI Contribution I have designed the experimental approach and generated a range of samples that are currently studied by both teams.
Collaborator Contribution The Department of Dermatology has a broad access to the skin samples from the University Hospital and the excellent facilities allowing isolation, expansion and characterisation of primary cell cultures from the human skin and hair follicles.
Impact A range of primary cell cultures has been derived from the mesenchymal component of human hair follicle and differentiated according to their inductive capacities or stem cell potential. These unique samples have been characterised using cell biology methods and the microarray approach.
Start Year 2007