A combination of metformin and galantamine exhibits synergistic benefits in the treatment of sarcopenia.

Age-associated sarcopenia, characterized by a progressive loss in muscle mass and strength, is the largest cause of frailty and disability in the elderly worldwide. Current treatments involve nonpharmacological guidelines that few subjects can abide by, highlighting the need for effective drugs. Preclinical models were employed to test the benefits of RJx-01, a combination drug composed of metformin and galantamine, on sarcopenia. In worms, RJx-01 treatment improved lifespan, locomotion, pharyngeal pumping, and muscle fiber organization. The synergistic effects of RJx-01 were recapitulated in a transgenic mouse model that displays an exacerbated aging phenotype (Opa1-/-). In these mice, RJx-01 ameliorated physical performance, muscle mass and force, neuromuscular junction stability, and systemic inflammation. RJx-01 also improved physical performance and muscle strength in 22-month-old WT mice and also improved skeletal muscle ultrastructure, mitochondrial morphology, autophagy, lysosomal function, and satellite cell content. Denervation and myofiber damage were decreased in RJx-01-treated animals compared with controls. RJx-01 improved muscle quality rather than quantity, indicating that the improvement in quality underlies the beneficial effects of the combination drug. The studies herein indicate synergistic beneficial effects of RJx-01 in the treatment of sarcopenia and support the pursuit of RJx-01 in a human clinical trial as a therapeutic intervention for sarcopenia.

Loss of Hematopoietic Cell-Derived Oncostatin M Worsens Diet-Induced Dysmetabolism in Mice.

Innate immune cells infiltrate growing adipose tissue and propagate inflammatory clues to metabolically distant tissues, thereby promoting glucose intolerance and insulin resistance. Cytokines of the IL-6 family and gp130 ligands are among such signals. The role played by oncostatin M (OSM) in the metabolic consequences of overfeeding is debated, at least in part, because prior studies did not distinguish OSM sources and dynamics. Here, we explored the role of OSM in metabolic responses and used bone marrow transplantation to test the hypothesis that hematopoietic cells are major contributors to the metabolic effects of OSM. We show that OSM is required to adapt during the development of obesity because OSM concentrations are dynamically modulated during high-fat diet (HFD) and Osm-/- mice displayed early-onset glucose intolerance, impaired muscle glucose uptake, and worsened liver inflammation and damage. We found that OSM is mostly produced by blood cells and deletion of OSM in hematopoietic cells phenocopied glucose intolerance of whole-body Osm-/- mice fed a HFD and recapitulated liver damage with increased aminotransferase levels. We thus uncovered that modulation of OSM is involved in the metabolic response to overfeeding and that hematopoietic cell-derived OSM can regulate metabolism, likely via multiple effects in different tissues.

Fenofibrate increases circulating haematopoietic stem cells in people with diabetic retinopathy: a randomised, placebo-controlled trial.

AIM/HYPOTHESIS: In two large RCTs, fenofibrate reduced the progression of diabetic retinopathy. We investigated whether fenofibrate increases circulating haematopoietic stem/progenitor cells (HSPCs), which have vascular properties and have been shown to protect from retinopathy. METHODS: We conducted a 12 week parallel-group RCT comparing fenofibrate vs placebo. Patients with diabetic retinopathy and without other conditions that would affect HSPCs were enrolled at a tertiary diabetes outpatient clinic and randomised to receive fenofibrate or placebo based on a computer-generated sequence. Patients and study staff assessing the outcomes were blinded to group assignment. The primary endpoint was the change in the levels of circulating HSPCs, defined by expression of the stem cell markers CD34 and/or CD133. Secondary endpoints were the changes in endothelial progenitor cells, lipids, soluble mediators and gene expression. We used historical data on the association between HSPCs and retinopathy outcomes to estimate the effect of fenofibrate on retinopathy progression. RESULTS: Forty-two participants with diabetic retinopathy were randomised and 41 completed treatment and were analysed (20 in the placebo group and 21 in the fenofibrate group). Mean age was 57.4 years, diabetes duration was 18.2 years and baseline HbA1c was 60 mmol/mol (7.6%). When compared with placebo, fenofibrate significantly increased levels of HSPCs expressing CD34 and/or CD133. CD34+ HSPCs non-significantly declined in the placebo group (mean ± SD -44.2 ± 31.6 cells/106) and significantly increased in the fenofibrate group (53.8 ± 31.1 cells/106). The placebo-subtracted increase in CD34+ HSPCs from baseline was 30% (99.3 ± 43.3 cells/106; p = 0.027) which, projected onto the relationship between HSPC levels and retinopathy outcomes, yielded an OR of retinopathy progression of 0.67 for fenofibrate vs placebo. Endothelial differentiation of CD34+ cells, estimated by the %KDR (kinase insert domain receptor) expression, was significantly reduced by fenofibrate. Fenofibrate decreased serum triacylglycerols, but the change in triacylglycerols was unrelated to the change in HSPCs. No effect was observed for endothelial progenitor cells, cytokines/chemokines (stromal-cell derived factor-1, vascular endothelial growth factor, monocyte chemoattractant protein-1) and gene expression in peripheral blood mononuclear cells. CONCLUSIONS/INTERPRETATION: Fenofibrate increased HSPC levels in participants with diabetic retinopathy and this mechanism may explain why fenofibrate reduced retinopathy progression in previous studies. TRIAL REGISTRATION: ClinicalTrials.gov NCT01927315.

Inhibition of SGLT2 Rescues Bone Marrow Cell Traffic for Vascular Repair: Role of Glucose Control and Ketogenesis.

The mechanisms by which sodium-glucose cotransporter 2 inhibitors (SGLT2i) improve cardiovascular outcomes in people with diabetes are incompletely understood. Recent studies show that SGLT2i may increase the levels of circulating cells with vascular regenerative capacity, at least in part by lowering glycemia. In this study, we used mice with streptozotocin-induced diabetes treated with the SGLT2i dapagliflozin at a dose that reduced glucose levels by 20%. Dapagliflozin improved the diabetes-associated defect of hematopoietic stem cell mobilization after stimulation with granulocyte colony-stimulating factor. Dapagliflozin rescued the traffic of bone marrow (BM)-derived cells to injured carotid arteries and improved endothelial healing in diabetic mice. Defective homing of CD49d+ granulocytes was causally linked with impaired endothelial repair and was reversed by dapagliflozin. The effects of dapagliflozin were mimicked by a similar extent of glucose reduction achieved with insulin therapy and by a ketone drink that artificially elevated ß-hydroxybutyrate. Inhibition of endothelial repair by resident cells using the CXCR4 antagonist AMD3100 did not abolish the vascular effect of dapagliflozin, indirectly supporting that endothelial healing by dapagliflozin was mediated by recruitment of circulating cells. In summary, we show that dapagliflozin improved the traffic of BM-derived hematopoietic cells to the site of vascular injury, providing a hitherto unappreciated mechanism of vascular protection.