The Mice Drawer System (MDS) Experiment and the Space Endurance Record-Breaking Mice

Abstract

The Italian Space Agency, in line with its scientific strategies and the National Utilization Plan for the International Space Station (ISS), contracted Thales Alenia Space Italia to design and build a spaceflight payload for rodent research on ISS: the Mice Drawer System (MDS). The payload, to be integrated inside the Space Shuttle middeck during transportation and inside the Express Rack in the ISS during experiment execution, was designed to function autonomously for more than 3 months and to involve crew only for maintenance activities. In its first mission, three wild type (Wt) and three transgenic male mice over-expressing pleiotrophin under the control of a bone-specific promoter (PTN-Tg) were housed in the MDS. At the time of launch, animals were 2-months old. MDS reached the ISS on board of Shuttle Discovery Flight 17A/STS-128 on August 28th, 2009. MDS returned to Earth on November 27th, 2009 with Shuttle Atlantis Flight ULF3/STS-129 after 91 days, performing the longest permanence of mice in space. Unfortunately, during the MDS mission, one PTN-Tg and two Wt mice died due to health status or payload-related reasons. The remaining mice showed a normal behavior throughout the experiment and appeared in excellent health conditions at landing. During the experiment, the mice health conditions and their water and food consumption were daily checked. Upon landing mice were sacrificed, blood parameters measured and tissues dissected for subsequent analysis. To obtain as much information as possible on microgravity-induced tissue modifications, we organized a Tissue Sharing Program: 20 research groups from 6 countries participated. In order to distinguish between possible effects of the MDS housing conditions and effects due to the near-zero gravity environment, a ground replica of the flight experiment was performed at the University of Genova. Control tissues were collected also from mice maintained on Earth in standard vivarium cages.

Spaceflight Influences both Mucosal and Peripheral Cytokine Production in PTN-Tg and Wild Type Mice

“…Decreased bone density and bone mass are issues associated with space flight [8]. The PTN-Tg mouse model was selected for the leading study in the MDS mission flown aboard the ISS, in order to determine whether PTN over-expression would provide protection from bone loss due to microgravity [8], [11]. The aim of present study was to examine effects of long-term space flight on immune parameters and the gut microbiota, through participation in a tissue-sharing program [11].…”

Changes in mitochondrial homeostasis and redox status in astronauts following long stays in space

“…Nutelings et al . suggested that three months of exposure to space conditions induced skin atrophy and deregulated hair growth in mice that were maintained in the Mice Drawer System (MDS)60 for 91 days aboard the ISS61. Another recent study conducted in space during the STS-135 mission, where female C57BL/6 mice survived for 13 days, resulted in increased oxidative stress in the skin, which was assessed by examining 4-hydroxynonenal (4-HNE)62.…”

Environmental Enrichment in the ISS Rodent Habitat Hardware System

“…Several notable behavioral activities have been observed during space experiments, including floating, hanging, and holding on to the cage bars (Cancedda et al, 2012). The mice adapted quickly to microgravity locomotion by using their paws and tails to grasp the cage's grid walls.…”

“…Besides motion based behaviors, the mice interacted readily with additional stimuli, if present. The incorporation of stimuli and other pieces of environmental enrichment could greatly influence the wellbeing of these test rodents in space (Cancedda et al, 2012).…”