Transcriptional analysis of dorsal skin from mice flown on the RR-6 mission

There were two Baseline groups of animals sacrificed (LAR Baseline & FLT Baseline; N=20; 40 animals; ~36 weeks old) at Kennedy Space Center (KSC; 12/9/17). A Ground Control group mimicked the Flight LAR group, which was housed at KSC, then shipped alive, to Novartis' facilities, where both the LAR and LAR Ground Control groups were processed (~41 weeks old; 1/16/18). All were anesthetized with isoflurane, blood samples were obtained by closed-chest cardiac puncture, and the animals were euthanized by exsanguination and thoracotomy.

The 20 ISS Terminal mice were anesthetized via intraperitoneal injection of ketamine/xylazine/acepromazine over the course of a four days of dissections (2/6/18 until 2/9/18; 53-56 days after launch; 44 weeks old at time of on-orbit dissections). Blood samples and euthanasia were conducted the same as LAR and Baseline. Following blood draw and hind limb dissection, the ISS-terminal animal carcasses were wrapped in aluminum foil, placed in a ziploc bag and placed in storage at -80C or colder until return.

The ISS-terminal Ground Controls (at KSC) followed the same euthanasia timeline, methods, and preservation. The final processing of frozen ISS-terminal, frozen ISS-terminal Ground Controls and frozen 0-day FLT baseline animals were completed at Houston Methodist Research Institute, in Houston, TX (5/21/18 until 5/24/18). GeneLab received samples of dorsal skin from only sham treated animals (no drug treated animals) from the following groups Flight: LAR (n=9), ISS Terminal (n=9); Ground Controls: LAR GC (N=9), ISS Terminal GC (N=10), LAR Baseline (n=10), ISS Terminal Baseline (n=6).

Total RNA was extracted and sequenced at a target depth of 60 M clusters per sample (ribodepleted, paired end 150).