Session 2
Biomedical research –
Strengths & imitations
of non-animal alternatives
In vitro liver systems:
modelling
and two-photon based
imaging
Jan G. Hengstler
IfADo-Leibniz Research
Centre
TU Dortmund
European Commission
Scientific Conference
December 6-7,
2016
Brussels
Example of a liver in vitro system
Primary human hepatocytes cultivated as spheres or cell sheets
Frey O, Hengstler JG, et al.,
Nat Commun 2014, 30;5:4250
Two-photon microscopy
Functional analysis
of intact tissues
Visualization of
mitochondria
Injection of Rhodamine
● Fluorescein-labeled bile acid analog
● Closely parallels the transport
properties of cholic acid derivatives
Transport of Cholyl-l-Lysyl-
fluorescein (CLF)
Possibilities
• Prediction of compounds that inhibit or induce
liver enzymes
• Identification of the main metabolites of a drug
• Prediction of acute toxicity
Limitations
• No microvessels (sinusoids) and therfore not
linked to circulaing imune cells
• Limitations in prediction of repeated dose
toxicity
• Limitations in recapitulating liver physiology
Liver in vitro systems In vitro
In vivo
Vartak N, …, Hengstler JG, Hepatology, 2016
Systems Modelling: Experiments with artificial cells organs
Examples:
Zeigerer A,.., Hengstler JG,…
Zerial M, Nature 2012;
485(7399):465-70.
Ghallab A, …, Hengstler JG, J Hepatol 2016; 64(4):860-71.
(Ghallab A, …, Hengstler JG,
J. Hepatol, 2016)
Integrate
functional
principles
(e.g. metabolic
pathways)
Systems modeling: The concept of tissues in silico
3D tissue
reconstruction
Compare the
result of the
simulation to
the in vivo
result
Identify missing mechanisms
and integrate them into
the model
Iterative cycles
New concept
to treat
hyper-
ammonemia
Breakdown of metabolic
detoxifying functions
of the liver (Ghallab et al.,
J. Hepatol, 2016)
Prediction of adaptive
versus adverse
responses to toxic
stress (Vartak et al.,
Hepatology, 2016)
Simulation of signal
transduction and decisionn
making in immune cells
(Cohen et al, Blood,
2013)
Modelling of cognitive
stimulation effects (Voss et al., Nat Neurosci.
2014)
Predict human
behaviour in human-
machine-interaction (Schlagkamp et al.,
HPCS, 2016)
Systems
modeling
Sub-
cellular
Cellular Organ
level
Orga-
nism
Control factors
of number and
size of
organelles (Zeigerer et al.,
Nature, 2012)
How to avoid a frustrating discussion
Please do not demonise others!
GAIA ACTION
29 November 2016
Insufficient animal testing may
cause human suffering
S-Thalidomide
Undercover in the University Hospital,
Jette Campus of the Free University of
Brussels (VUB): GAIA reveals intolerable
suffering of research animals
Recommendations for discussion
Accept that we need animal experiments in clinical and basic research
- a ban of animal experiments is no option
Define concrete strategies to reduce, replace and refine
- The pre-test principle
- Define concrete endpoints where animals are no
longer needed
- Establish in vitro systems that can be interpreted with respect
to the in vivo situation
- Systems modeling for a better planning of experiments
Replacement of a large fraction of animal experiments is an
attractive long term goal;
However, establishment of the required in vitro systems and
modelling techniques is a challenge for 1-2 generations of
scientists
Scientists under pressure: avoid isolation and unwise responses to
double standards
An example of double standards
At least 10-fold more animal are killed by rotenicides than by animal experiments
Slow and painful death by internal bleeding
No license
needed
No visible
protests
from activists
Scientists under pressure: avoid isolation and unwise responses to
double standards
Double standards of activists and politics do not release sientists
from their duty to explain the benefit of their findings to the public:
Most pharmaceuticals were discovered based on animal experiments
Modern medicine would be impossible without the knowledge gained
From animal experiments
Use all possibilities to reduce, replace and refine
Politicians, scientists and acitivists: Communicate!