Fig 2: CTSB Skeletal Muscle Protein and Transcript Response to 80% Acute Aerobic Exercise. A) Representative western blot probing for CTSB before, 30-minutes post and 3-hours post 80% acute AE. All samples were normalized to total protein stain. Protein and transcript content of B) Mature CTSB protein, C) ProCTSB protein, D) Total CTSB protein and E) Pro:Mature CTSB protein ratio and F) CTSB transcript n = 15 (8M/7F). Mature CTSB is expected at 30 kD, ProCTSB is expected at 41 KD. All data are represented as mean±SEM. n = 13 PRE (7M/6F), n = 6 POST (5M/1F), and n = 6 3 h (4M/2F). *p < 0.05 vs PRE, **p < 0.01 vs PRE, #p < 0.05 main effect of time.

Fig 3: Single protein-injection of CALU or SOD1 improved glucose control. (A) Nonfasting plasma glucose levels measured from days 0-42 in mice iPan-injected with basal media (vehicle control, n = 7), 8-protein combination (n = 7), or each of the eight proteins individually (CALU, n = 6; SOD1, n = 6; CTSB, n = 7; FAM3C, n = 6; GAL1, n = 7; PSAP, n = 6; TGM2, n = 8; and PPIA, n = 6). (B) Area under the curve for plasma glucose (AUC P.G.) was reduced in mice iPan-injected with 8-protein combination, CALU, and SOD1. (C) Fasting plasma glucose was measured for 120 min following intraperitoneal injection of a glucose bolus and (D) area under the curve for fasting plasma glucose during the glucose tolerance test was lower in mice that were iPan-injected with 8-protein combination, CALU, SOD1, or CTSB, compared to basal media-injected controls. (E) Islet size was increased in mice iPan-injected with 8-protien combination and SOD1, while (F) beta cell mass was increased in mice iPan-injected with 8-protein combination, compared to basal media-injected controls. Dashed line represents data obtained from healthy controls (n = 6). Data represent mean ± SEM. Glucose data was compared using two-way ANOVA followed by Dunnett’s multiple comparisons test. AUC was compared using one-way ANOVA followed by Dunnett’s multiple comparison test (*P < 0.05, **P < .01 vs basal media).

Fig 4: CTSB Skeletal Muscle Protein and Transcript Response to 80% Acute Aerobic Exercise. A) Representative western blot probing for CTSB before, 30-minutes post and 3-hours post 80% acute AE. All samples were normalized to total protein stain. Protein and transcript content of B) Mature CTSB protein, C) ProCTSB protein, D) Total CTSB protein and E) Pro:Mature CTSB protein ratio and F) CTSB transcript n = 15 (8M/7F). Mature CTSB is expected at 30 kD, ProCTSB is expected at 41 KD. All data are represented as mean±SEM. n = 13 PRE (7M/6F), n = 6 POST (5M/1F), and n = 6 3 h (4M/2F). *p < 0.05 vs PRE, **p < 0.01 vs PRE, #p < 0.05 main effect of time.

Fig 5: Effects of Acute Aerobic Exercise Intensity on Circulating CTSB. Circulating CTSB before and 30-minutes post AE A) 40% of VO2max, B) 65% of VO2max, C) 80% of VO2max and D) at VO2max. n = 15 (9M/6F) 80% VO2max, n = 16 (10M/6F) all other timepoints. All data are represented as mean±SEM. *p < 0.05 vs PRE.