Effect of spaceflight
and hypergravity on mineral metabolism in organ cultures of fetal mouse
long bones.
Jack J.W.A. van
Loon
Free University Amsterdam, 23 March 1995.
Promotoren: prof.dr. E.H. Burger
Copromotor: dr. J.P. Veldhuijzen
Referent: prof.dr.ir R. Huijskes
Contents:
Chapter 1
Bone and Spaceflight: An Overview
Published in: Jack J.W.A. van Loon, J. Paul Veldhuijzen, Elizabeth H. Burger. Bone and space flight: an overview. in Biological and Medical Research in Space, Edt. D. Moore, P. Bie and H. Oser. Springer-Verlag Berlin Heidelberg, Chapter 5, 259-299, 1996.
Chapter 2
Development of Tissue Culture Techniques and Hardware to Study Mineralization
under Microgravity Conditions.
J.J.W.A. van Loon1,
J.P. Veldhuijzen1, E.J. Windgassen2, T. Brouwer3, K. Wattel3, M. van Vilsteren3
and P. Maas4. Academic Centre for Dentistry Amsterdam (ACTA), Dept. of Oral
Cell Biology1 and Dept. of Engineering2 and Vrije Universiteit, Fac. of
Biology, Dept. of Electronics3, and of Engineering4. Amsterdam, The Netherlands.
Abstract
To study the effects of weightlessness on fetal mouse long bone rudiment
growth and mineralization we have developed a tissue culture system for
the Biorack facility of Spacelab. The technique uses standard liquid tissue
culture medium, supplemented with Na-ðb-glycerophosphate, confined in gas
permeable polyethylene bags mounted inside ESA Biorack Type-I experiment
containers. The containers can be flushed with an air/5% CO2 gas mixture
necessary for the physiological bicarbonate buffer used. Small amounts of
fluid can be introduced at the beginning (e.g. radioactive labels for incorporation
studies) or at the end of the experiment (fixatives). A certain form of
mechanical stimulation (continuous compression) can be used to counteract
the, possibly, adverse effect of microgravity. Using 16 day old metatarsals
the in vitro calcification process under microgravity conditions can be
studied for a 4 day period.
Published in: Adv. Space Res. 14(8), 289-298, 1994.
Chapter 3
Decreased Mineralization and Increased Calcium Release in Isolated Fetal
Mouse Long Bones under Near Weightlessness.
Jack J.W.A. van Loon, Dirk-Jan Bervoets, Elisabeth H. Burger, Suzanne C.
Dieudonné, Jan-Willem Hagen, Cor M. Semeins, Behrouz Zandieh Doulabi,
J. Paul VeldhuijzenAcademic Centre for Dentistry Amsterdam (ACTA), Dept.
of Oral Cell Biology, Amsterdam, The Netherlands.
Abstract
Mechanical loading plays an important role in the development and maintenance
of skeletal tissues. Sub-normal mechanical stress as a result of bed rest,
immobilization, but also in spaceflight, results in a decreased bone mass
and disuse osteoporosis, whereas supra-normal loads upon extremities result
in an increased bone mass.In this first in vitro experiment with complete
fetal mouse cartilaginous long bones, cultured under microgravity conditions,
we studied growth, glucose utilization, collagen synthesis, and mineral
metabolism, during a 4 day culture period in space. There was no change
in %length increase and collagen synthesis under microgravity compared to
in-flight 1×gravity. Glucose utilization and mineralization were decreased
under microgravity. In addition mineral resorption, as measured by 45calcium
release, was increased.These data suggest that weightlessness has modulating
effects on skeletal tissue cells. Loss of bone during spaceflight could
be the result of both impaired mineralization as well as increased resorption.
Published in: J Bone Min Res, 10(4), 1995.
Chapter 4
Polysulphone Inhibits Final Differentiation Steps of Osteogenesis In Vitro.
Jack J.W.A. van Loon1,
Johan Bierkens2, Jef Maes2, Greet E.R. Schoeters2, Daniella Ooms2, Behrouz
Zandieh Doulabi1, J.Paul Veldhuijzen1. 1
Academic Centre for Dentistry Amsterdam (ACTA), Dept. of Oral Cell Biology,
Amsterdam, The Netherlands. 2 Flemish Institute for Technological Research
(VITO), Environmental Division, Mol, Belgium.
Abstract
Biocompatibility is an important factor in the development of orthopaedic
implants as well as in the development of new tissue culture devices. Polysulphone
has been used for orthopaedic implants because of its mechanical properties,
ease of sterilization, its molding capacity and its biocompatibility. Therefore
polysulphone has been chosen as the prime material for the construction
of tissue culture devices to be used for cultivation of osteogenic cells
(pre-osteoblast-like MN7 cells and primary bone marrow fragments) as well
as complete fetal long bone explants under space flight conditions. Whereas
polysulphone did not interfere with the proliferation in early stages of
bone forming cells, we show that leacheble factors within the polysulphone
polymer prevented the final steps of matrix formation as measured by collagen
synthesis and matrix mineralization. These data argue against polysulphone
is a material for orthopaedic implants.
Published in: J. Biomed. Mat. Res. Vol 29, pp 1155-1163, 1995.
Chapter 5
Reduced Mineralization in Isolated Fetal Mouse Long Bones Flown on Board the
Russian Bion-10 Satellite.
Jack J.W.A. van Loon1,
Olga Berezovska2, Behrouz Zandieh Doulabi1, Cor M. Semeins1, Natalia V. Rodionova2,
J. Paul Veldhuijzen1. 1: Academic
Centre for Dentistry Amsterdam (ACTA), Dept. of Oral Cell Biology, Amsterdam,
The Netherlands. 2: I.I. Shmalgauzen Institute of Zoology of the Academy of
Sciences of the Ukraine, Kiev, The Ukraine.
Abstract
Skeletal tissues are sensitive for their mechanical environment. Mechanical
forces due to every day weight bearing ambulatory activities are necessary to
maintain skeletal integrity. An exceptional situation of a reduced mechanical
environment is near weightlessness as a consequence of orbital spaceflight.
Several papers have indicated already that the near weightlessness environment
of space results in detrimental effects on bone matrix and/or mechanical strength.
From these in vivo studies it is not clear, however, whether the effects are
the results of a lack of load bearing on the skeleton or whether they are, due
to hormone changes or body fluid shifts as a result of entering microgravity.
For the present study we used organ cultures of mouse long bones as were also
flown in a previous manned Space Shuttle flight. During this unmanned Russian
Cosmos-2224 mission, however, the rudiments were cultured in completely automated
tissue culture devices for a period of 4 days. The results contribute to our
earlier observations and show that also in this completely automated experiment,
fetal long bone growth was not affected by microgravity, while matrix mineralization
was decreased compared to the 1×g control conditions.
Chapter 6
Increased Mineralization and Calcium Release in Fetal Mouse Long Bones Cultured
under Hypergravity Conditions.
Jack J.W.A. van Loon,
J. Paul Veldhuijzen. Academic Centre for Dentistry Amsterdam (ACTA), Dept.
of Oral Cell Biology, Amsterdam, The Netherlands.
Abstract
It is now well documented that skeletal tissues and cells are sensitive
to their mechanical environment. It has been shown previously that fetal
mouse metatarsal long bone rudiments respond with an increased mineralization
and reduced mineral resorption when subjected to an intermittent (1/3 Hz)
hydrostatic compression of 13 kPa above ambient, while in culture.(11,12)
In the present study we applied gravitational forces, or accelerations,
of 2.2×g on bone rudiments for four to five days in organ culture, to study
the effect of a vectorial force similar long on longitudinal growth and
mineral metabolism. In the mineralization model, using 16 day old bones,
2.2×g hypergravity stimulated cartilage growth by 28% and increased mineralization,
as indicated by a more than 4 times longer calcified diaphysis as well as
more than 7 times higher 45Ca incorporation. In addition, in the resorption
model, using 17 day old bones, hypergravity increased mineral resorption
by 37% compared to 1×g controls. This data suggests that both growth and
mineral metabolism in fetal bones are sensitive to mechanical stress resulting
from hypergravity during organ culture.