Functional testing of kidneys tissue-engineered from renogenic stem cells.

Lead Research Organisation: University of Edinburgh
Department Name: Centre for Discovery Brain Sciences

Abstract

Lay summary

This project is about a new approach to the challenge of engineering complex organs for medical purposes.

One of the most pressing goals of biological engineering is to find a way to make a functioning, transplantable organ from a simple culture of stem cells. Success in this area will bring direct benefits to patients, economic relief to the NHS and taxpayer, and will provide significant opportunity for industries who take up the challenge of producing organs to order.

Existing work in the biotech industries has centred mainly on making clinical grade stem cells and setting them up to make specific tissues. The gap between cultures of stem cells, which are essentially un-arranged, and the highly intricate anatomical arrangements of complex organs such as kidney remains unbridged. Until the gap is bridged, stem cells will be of only very limited practical use for patients with serious organ failures.

We have recently developed and published a novel engineering technique for turning a simple suspension of individual foetal stem cells into a 'mini-kidney', essentially identical to a real foetal kidney except that it has no blood system. We now propose to engineer in a blood system, and to test the ability of our engineered kidneys to filter blood and excrete substances as a normal kidney would. We also propose to test how robust our method is (how well it corrects errors automatically, as we expect it to).

The direct impact of this project will be to provide an engineering technique by which kidney stem cells can be used to build real organs, potentially useful for transplants. In addition, we expect our technique to be applicable to other organs and tissues, so it may have a much broader impact in the general area of biological engineering.

Technical Summary

This proposal addresses a priority area of MRC-MCMB: tissue engineering for regenerative medicine. It will test the physiological function of 'kidneys' tissue-engineered by a method developed in this lab: an important step in closing the gap between cultured stem cells and transplantable organs.

We have published a 2-step technique that turns suspensions of embryonic kidney stem cells into all of the epithelial and mesenchymal structures of a typical foetal kidney (Bowman's capsule, proximal and distal tubule, collecting duct, stroma etc), arranged and connected correctly, and we have pilot data showing that these engineered kidneys will become vascularized and will filter blood when transplanted into an adult host. We now wish to test, robustly and quantitatively, their functional ability:

1) We will add endothelial cells, grafted vessels in normal culture, and chick endothelia in chorioallantoic membrane (CAM) culture, to assess the ability of engineered kidneys to construct an anatomically-correct blood system.
2) We will use the fact that blood will be flowing in the CAM system (powered by the chick embryo heart) to test glomerular filtration using a standard labelled tracer method.
3) We will test active transport of organic anions and cations in the proximal tubules using labelled tracers: this will not depend on the success of parts 1 and 2 because it does not require flowing blood.
4) We will assess the robustness of the engineering system and its ability to self-correct deliberately-introduced errors of cell balance and arrangement. We have theoretical grounds to expect this.

Overall, this proposal advances our existing re-creation of basic renal anatomy to determining functional attributes. Afterwards, if the engineered organs perform as well as we expect, we can justify testing their ability to substitute for natural kidney function when matured in adult hosts. The self-organization based technology has more general biotech implications.

Planned Impact

Impact Summary

There are 5 main classes of beneficiaries; they are listed here in order of immediacy (time) of direct impact;
1 - Academic bio-engineers (impact within time-scale of project)
2 - Biotech industry (impact probably just after project, maybe during)
3 - Public (meaningful impact several years away, but along a clear development path).
4 - Government (ditto).
5 - Third sector (ditto).

Academic research: Direct benefit to others trying to engineer complex tissues, as our technique is probably applicable far beyond the kidneys on which this project will focus. This impact on the academic community that can broaden the range of applicability of the engineering technique is a multiplier of all of the benefits below. There is also a small benefit to basic scientific understanding, which is detailed in the Case for Support section.

Biotech: The most direct benefit to biotech will be a viable engineering path from stem cells to *complex* organs (at the moment, only simple tissues can be made). This is a big multiplier of value already invested in stem cell technology, and can impact profit, growth and range of application. The type of work is ideally suited to UK SMEs. A second, small effect, comes from the training of people (who attend our proposed workshop, open to industry as well as academia) in exactly these techniques. Biotech, as well as academia, can research applying our engineering techniques to other tissues and organs.

Public: the shortage of transplantable kidneys (waiting list c. 7000 and growing) causes significant suffering (dialysis is painful, time-consuming and robs people of freedom and productivity). A technique for engineering kidneys from stem cells would provide great benefit; even more if it could be applied to other organs too. Plus, of course, indirect benefits from growth of a vibrant biotech industry.

Government: Maintaining kidney patients on dialysis is doubly expensive; directly to the NHS and also in respect to loss of time from individuals hooked up to a dialysis machine when they could be productive. Production of transplantable organs would alleviate both problems. ALSO, government research councils have ploughed a lot of money into stem cells without much to show for it in terms of a medical advance that the taxpayer can see and feel has been value. Having a bridge from stem cells to organs would be a valuable concrete example of why funding research is useful.

Third Sector: medical charities will have the same benefit as mentioned above for government research councils.
 
Description Asked to co-chair KRUK regenerative medicine strategy committee and research network
Geographic Reach National 
Policy Influence Type Participation in a advisory committee
URL https://www.kidneyresearchuk.org/research/uk-renal-regenerative-medicine-network
 
Description Kidney Research UK PhD studentship
Amount £62,926 (GBP)
Funding ID ST_001_20161116 
Organisation Kidney Research UK 
Sector Charity/Non Profit
Country United Kingdom
Start 10/2017 
End 09/2020
 
Description Kindey Research UK Project Grants
Amount £197,000 (GBP)
Funding ID RP_002_20160223 
Organisation Kidney Research UK 
Sector Charity/Non Profit
Country United Kingdom
Start 03/2017 
End 08/2019
 
Title Method for including a urothelial exist tubule in renal organoids 
Description An improvement to methods of renal organoid production, to make more realistic renal organoids that include a ureter-type urothelium as an exit for the collecting duct tree. 
Type Of Material Technology assay or reagent 
Year Produced 2017 
Provided To Others? Yes  
Impact This is being written immediately after publication of the work - too early to state impacts. 
URL https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5665994/
 
Title Method for testing renal transport in micro-culture 
Description The new thing is a method, to be used on tissue-engineered kidneys (which are also a research material from this lab, but from earlier grants). 
Type Of Material Physiological assessment or outcome measure 
Provided To Others? No  
Impact We are only in month 4 of our 36 month grant - we have this method working, and will use it for the stated aims of this grant. (We have just submitted a paper describing it, to Scientific Reports) 
 
Description Astra-Z~eneca Tox screen 
Organisation AstraZeneca
Country United Kingdom 
Sector Private 
PI Contribution The point of this was to test whether our iPS-derived organoids are physiologically realistic enough to be useful for screening candidate drugs for nephrotoxicity, directly in a human-based system and so avoiding interspecies differences commonly stumbled over in animal-based tests. We built many human iPS cell-derived organoids and applied blind-coded test compounds (some known nephrotoxicants, some controls) to them. We conducted our own assays of cell stress, and also sent RNA and media to our partner for analysis.
Collaborator Contribution Supply of the blind-coded test compounds, and analysis of transcripts and metabolites.
Impact We have an interim but commercially confidential result: we (both halves of the partnership) intend to publish soon but until we do we are bound by the confidentiality agreement.
Start Year 2015
 
Description Peter Hohenstein Renal Development 
Organisation University of Edinburgh
Department The Roslin Institute
Country United Kingdom 
Sector Academic/University 
PI Contribution Expertise in renal organ culture, engineering and physiological measurement
Collaborator Contribution Expertise in genetic manipulation of mice and mouse cells.
Impact 6 published research papers, two more in current review, nd several joint grant applications.
 
Description Renotox collaboration wiht A-Z 
Organisation AstraZeneca
Country United Kingdom 
Sector Private 
PI Contribution Expertise in in vitro renal organoids
Collaborator Contribution Expertise in toxicology, and a blind-coded panel of reagents
Impact Currently confidential under our agreement with Astra-Zeneca
Start Year 2016
 
Description A tissue engineering approach to reduce animal use in renal development and renal organ replacement technology 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact About 70 scientists attended, and discussed this work. Informal discussions afterwards led to the dissemination impacts below.

Dissemination of cell lines created in the project to other labs (France, UK, Australia), and dissemination of ordering details vie www.gudmap.org database.
Year(s) Of Engagement Activity 2011
 
Description Broadcast on BBC World Service 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Participation in a 3-way discussion (+ Bridget Kendal as Chair) for a 50-minute BBC World Service "Forum" programme, on mechanisms of self-assembly and self-organization. This included discussion of the MRC-funded renal tissue engineering project, and the BBSRC-funded synthetic morphology project although I am afraid the specific sentence about funding this was lost on the edit.

No directly measurable ones (and none were expected - this was about show-casing an interesting field of science to a world-wide pubic audience).
Year(s) Of Engagement Activity 2014
URL http://www.bbc.co.uk/programmes/p027gcpk
 
Description Edinburgh Science Festival - event on 3Rs in action 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Multi-presenter presentation followed by audience Q&A on the ethical and practical dimensions of working with experimental animals and refining, reducing and replacing animals in research.
Year(s) Of Engagement Activity 2019
 
Description Manning a stall at the Transplant Games, Ravenscraig, Scotland 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Patients, carers and/or patient groups
Results and Impact Presence at a Kidney Research UK 'stall' (literature, videos, and a microscope with one of our engineered hiPS-based kidneys available for viewing). The main activity was talking to patients and carers (parents, mainly) about our work and about medical research in general. In some cases this included talking to young people about how they might enter medical research themselves (as researchers, not subjects).
Year(s) Of Engagement Activity 2017
 
Description Participation in Royal Society of Biology careers event 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Professional Practitioners
Results and Impact Workshops on careers for biology graduates, held at the University of Highlands and Islands, and attended mainly by professional careers advisors, with some undergraduate attendance too. It was intended for the careers advisors.
Year(s) Of Engagement Activity 2017
 
Description Pint of Science 2019 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Pint of Science event: two public engagement talks on a kidney theme (and arranged by Kidney Research UK), with an activity for the audience in between, all in a pub.
Year(s) Of Engagement Activity 2019
 
Description Pint of Science presentation 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Pint of Science pub-based talk and demonstration.
Year(s) Of Engagement Activity 2016
 
Description Presentation about Edinburgh kidney work to a specific altruistic donor (and family) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Supporters
Results and Impact At the request of Kidney Research UK, a specific presentation by a number of KRUK-funded researchers in Edinburgh to this supporter and his family.
Year(s) Of Engagement Activity 2019
 
Description Presentation of Young European Scientist's Event 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Undergraduate students
Results and Impact Talk and workshop at the Young European Scientist's Meeting at Porto (which, despite the name, is actually mainly medical students from around Europe)
Year(s) Of Engagement Activity 2016
 
Description Public talk at Aye Write (Glasgow literary festival) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact About 60 people attended a talk on human development, with some discussion afterwards, both about the talk and about career paths into science.

One school pupil came to shadow someone in the lab for a week.
Year(s) Of Engagement Activity 2014