Lab Spotlight: Fajardo Laboratory at Brock University

One research project, led by Ryan Baranowski (MSc), focused on investigating the potential of a specific protein to counteract the negative effects on muscle and bone health observed in mice exposed to spaceflight conditions. This study involved sending four groups of mice (RR9, RR1, RR18, BION-M1) to the International Space Station and separate satellites for a duration of 30-37 days. The protein in question, Glycogen Synthase Kinase-3 (GSK3), tends to be excessively active early in space travel, leading to muscle and bone loss, as well as changes in the composition of muscle fibers, particularly in the postural soleus muscle over the course of 30-37 days. To determine if reducing the activity of GSK3 in skeletal muscle could alleviate the muscle and bone deterioration, GSK3floxed (wildtype) and GSK3-knockdown (GSK3KD) mice were subjected to a simulated microgravity model known as hindlimb suspension for 7 days. Analysis using the iNSiGHT DXA system revealed that GSK3KD mice maintained their body weight over the 7-day period and exhibited a higher amount of lean body mass compared to the control group of wildtype mice. Furthermore, the soleus muscles of GSK3KD mice showed increased mass and cross-sectional area after hindlimb suspension in comparison to wildtype mice under the same conditions, and their muscle strength was similar to that of mobile control mice. 

In addition to muscle, their research found that space flight dramatically reduced bone mineral density, a common measure to diagnose osteoporosis here on earth. This result was also associated with an overactivation of GSK3 in the bone. Strikingly, their work also found that knocking down GSK3 in muscle offered some protective effects in the bone under the hindlimb suspension model. This reveals a potential a muscle to bone connection that Fajardo and his lab look forward to studying further