Influence of underlying matrix on induced pluripotent stem cell differentiation and integration of trabecular meshwork cells

There is an urgent need for further treatment options for the blinding condition of Glaucoma Unfortunately with age there is a progressive loss of cells (Trabecular meshwork) from the eye’s outflow pathway which is even more severe with patients with glaucoma. Replacing these lost cells may therefore have a therapeutic potential. We have shown there is subpopulation of cells (adult stem cells; ASCs) located in the eye that have the potential to repopulate the outflow pathway and wish to compare this ability with TM cells derived from induced pluripotent stem cells (iPSc). The biology of how these cells can repopulate the young or aged TM outflow pathway in our experimental models of young and aged TM is not yet understood. We can utilise 2 unique models in which decellularised TM explants can be repopulated (ex-vivo model) or an human organ culture anterior segment (HOCAS) perfusion model We hypothesis that the differentiation process will be influenced by the age and/or stiffness of the underlying matrix substrate.

Aims: We aim to investigate how young and old aged human cells (iPS and ASCs) differentiate and function on substrates (variations in age and stiffness) using our established in-vitro differentiation methods. In addition we aim to investigate the mechanism of differentiation in our two ex-vivo models (decellularised TM tissue & perfusion model) utilising our young and old tissue resources. As the TM cell numbers decrease and the meshwork support stiffens with both age and more so with glaucoma, understanding of their roles are hugely significant for future regeneration therapies.

Methods of investigation: We will utilise our stores of ASCs from glaucomatous and non- glaucomatous patients. These cells are derived from a wide range of patient ages giving us a unique study of the stem cell population. Progenitor cells obtained using our published techniques will be used alongside IPS-derived TM cells to assess their ability to differentiate on substrates of various states of rigidity. We have a number of substrates to evaluate which include ex-vivo decellularised Human TM tissue (aged and young); in-vitro TM-derived ECM (aged/non aged/glaucomatous non glaucomatous), ECM protein (e.g. laminin) as well as artificial substrates of various stiffness.
High throughput RNA sequencing small RNA-Seq. library preparation and sequencing has been performed and analysis of FASTQ sequencing files (Partek) has revealed candidate miRNA and mRNA involved in TM differentiation and will be used as a measure of differentiation.

Outcomes: There is growing evidence that cells can be delivered to the human outflow pathway and improve aqueous drainage. Our studies will fine tune delivery to the outflow pathway and further our understanding of the factors required to achieve this and how rigidity of the substrate can influence this repopulation from adult SC’s from IPS and TM populations. In addition the student will be well equipped to embark on a multidisciplinary research path following completion of their studies.

The supervisory team consists of an internationally recognised expert in Ophthalmology wound healing and regenerative research and an expert in pluripotent and adult stem cell biology, directed differentiation protocols and translational biology. The student will receive training in the molecular regulation and characterisation of pluripotent and adult stem cell biology, stem cell: matrix and material interactions, tissue engineering and cellular function studies. The student will also be enrolled in the Liverpool Doctoral College to develop skills including scientific communication, mathematical analyses and commercialisation of research.

Key words; stem cells, ophthalmology, regenerative medicine, transplantation, biomaterials,

The Institute of Ageing and Chronic Disease is fully committed to promoting gender equality in all activities. In recruitment we emphasize the supportive nature of the working environment and the flexible family support that the University provides. The Institute holds a silver Athena SWAN award in recognition of on-going commitment to ensuring that the Athena SWAN principles are embedded in its activities and strategic initiatives.

To apply: please send your CV and a covering letter to Dr Carl Sheridan [Email Address Removed] with a copy to [Email Address Removed]