Abstract
Introduction
The Scientific Committee of the Swiss Laboratory Animal Science Association (Schweizerische Gesellschaft für Versuchstierkunde, SGV) reports on the Annual SGV Meeting held on 28 and 29 November 2017, at Technopark, Zürich, Switzerland.
Feedback after the 2016 meeting and recent developments with regards to experimental reproducibility prompted the SGV Scientific Committee to cover reproducibility topics other than experimental design. Aging studies, humane endpoints, zebrafish and short communications were also presented.
The sessions were well attended with up to 400 participants per day. Meeting attendance counted as continued education for people carrying out procedures on animals and designing procedures and projects.
Summary of oral presentations
To kick off the 2017 meeting, the reproducibility presentations of the 2016 meeting were summarized and commented (titles shortened): Recognizing sloppy science (C Begley); Importance of replication studies (E Iorns); MULTI-PART initiative (M MacLeod); Animal Research: Reporting of In Vivo Experiments (ARRIVE) guidelines and Experimental Design Assistant (N Percie du Sert); Scientific validity of animal experiments in Switzerland (H Wuerbel); Animal experimental design (M Berdoy); Risk of bias in reports (SGV Awardee Lecture 2016, M MacLeod); Litter-to-litter variation (S Lazic); Lessons learned from animal experiment licenses (F Schuetz); Cells and antibodies: improving reproducibility (L Freedman); and Method reporting and the reproducibility crisis (S Cruickshank).
A brief overview of barriers preventing us from harnessing the potential of animal experiments was given. In addition, attrition bias is rarely considered in the current discussion on improving the value and predictiveness of preclinical research.
A register for preclinical studies would enable transparent and public access to valuable data and contribute to the increased reduction, replacement, refinement and reproducibility of preclinical studies, as well as improved translation to man.
Creation of a new discipline, studying how knowledge is gained from animal research, was proposed to improve the reproducibility and translatability of animal-based research, focusing on features of model biology, human biology, measures, animal welfare, experimental design and statistics, and of background methodology and husbandry.
All of the issues discussed ultimately boil down to considering the animal as a patient, not a tool.
Open Science ultimately relies on the willingness to share and collaborate, based on experiment outputs and how transparently those are reported.
Editors and publishers can help improve design and reporting standards by using reporting checklists. Challenges from a publisher’s perspective and two recent studies were presented. Changing the current evaluation system is one of the greatest challenges.
Mouse housing temperature influences tumour characteristics. Sub-thermoneutrality-induced chronic neoplastic sympathetic nerve stimulation and the production of norepinephrine are major factors in regulating anti-tumour immune cells, based on β2-adrenergic receptor signaling.
Checkpoint blockade immunotherapy combined with thermoneutral housing or β-blocker use significantly improved therapeutic efficacy in mice and suggests new treatment options in patients.
Differences in gut microbiota (GM) are associated with differences in rodent models of intestinal disease, but also in other physiological processes. GM changes can now be better controlled, but also serve as a tool to identify which microbes might be investigated further as potential contributors to health and disease.
Handling routine and the incorporation of non-aversive handling methods, such as the use of tunnels or hand-cupping in routine husbandry and experimental procedures, may reduce the level of anxiety and translate into robust test responses.
Social transfer of pain states to control mice is non-specific and also occurs in other laboratory rodents mainly through olfactory cues.
This indicates that physiological states can be communicated by experimental animals and mimicked by naïve ‘bystander’ controls, potentially affecting the interpretation of results. These findings call for reconsideration of the standard practice of housing experimental and control animals in the same rooms.
As both pain and analgesics can affect research outcomes, it is challenging to choose surgical anesthetics and postoperative analgesics to limit animal suffering best.
Scientists who publish full descriptions of animal procedures (see ARRIVE guidelines) allow critical and systematic data review, demonstrate their adherence to animal welfare norms and guide other scientists on how to conduct their own studies in the field.
The selection of strains for use in studies, existing data sources, breeding strategies, experimental design, parental influence and other metadata were discussed.
‘How old is old’? With ageing, the variability in phenotyping results tends to increase and standard phenotyping tests may not be applicable. There may be additional welfare concerns and it is critical to ensure that cage-side staff are familiar with ageing.
In studies of longevity or aging in mice, prolongation of lifespan can be an important measure of efficacy; premature euthanasia could significantly skew the data and lead to erroneous conclusions.
Practical objective accurate markers can signal the need for heightened monitoring, clinical intervention, preemptive euthanasia or study termination. Validated markers promote animal wellbeing of aged mice and facilitate the collection of valuable antemortem samples and measurements.
Researchers need to be familiar with how old mice appear clinically, at necropsy and histopathologically. This baseline knowledge is important for the determination of humane endpoints, defining health span, contributing causes of death and effects of interventions.
The presentation focused on what makes suffering severe, focusing on the nature, level and the duration of suffering, as well as the ability to escape or cope. The RSPCA, in liaison with scientific and regulatory communities, has developed a road map, endorsed by the UK Government, to ultimately end severe suffering of laboratory animals.
The RSPCA advocates good communication and teamwork when considering animal use, and ‘putting the ethics in’ with respect to the UK Animal Welfare and Ethical Review Body.
Interdisciplinary teamwork and good communication between scientists, veterinarians and caretakers is vital for a fuller understanding of the animal’s experience, promoting a paradigm change from ‘what am I doing to the animal’ to ‘what is the animal experiencing’. This interdisciplinary work has already led to the refinement of four animal models with severe suffering.
The efficacy of different euthanasia gases was evaluated in mice. The duration of seizures was shorter with CO2 but showed the longest time before loss of consciousness. Persisting brainwaves and indications of hypoxia suggest a conscious experience. This may indicate that alternatives to CO2 gas are required to reduce animal suffering during euthanasia.
Standardization protocols are necessary to ensure zebrafish welfare as well as the reproducibility of experimental procedures. A joint working group on zebrafish housing, husbandry and health monitoring has been given a mandate to address a Federation of Laboratory Animal Science Associations (FELASA) list of parameters, and to give recommendations for guidelines.
Automated intelligent monitoring software was developed to assess pain in zebrafish and allow timely intervention. Additionally, the efficacy of analgesic drugs can be determined, allowing the establishment of analgesic protocols.
Molecular techniques, in particular genome editing and transgenesis, have opened up many experimental avenues for models in fish, embryos and larvae. The discussion of evolutionary mutant models showed the value of fish species and models, other than zebrafish.
K Leech (European Animal Research Association, UK) covered ‘how to better communicate about animal experimentation’ to increase transparency and understanding by the public and policy makers.
In ‘Rodents have a right for asepsis’, S Zeiter (AO Research Institute Davos, Switzerland) stressed the importance of, and limited costs needed for, the performance rodent surgery under aseptic conditions.
O Guenat (University of Bern, Switzerland) and O Frey (InSphero AG, Switzerland) presented ‘Lungs on a chip’ and ‘Micro-engineering of multi-tissue systems’, respectively, demonstrating how in vitro models may serve as early screening tools and may eventually replace some animal experiments.
Note: This contribution to the News section has not been subjected to peer review and reflects the opinion of the subscribing society. All listed authors are active members of the SGV Scientific Committee (led by Dr Isabelle Desbaillets), with the exception of Dr Stefanie Schindler, who acted as 3R consultant.
ORCID iD
Mark Deurinck http://orcid.org/0000-0002-8842-0944 Stephan Zeiter http://orcid.org/0000-0002-8155-4202