Smoking Status Impacts Mitochondrial Function and Synthetic Function in Mesenchymal Stem Cells Derived from Diabetics
Dylan McLaughlin1,2, Maiko Sasaki1,2, Carson Hoffmann1,2
1Emory University School of Medicine, Atlanta, Georgia, USA.
Abstract:
Objective: Diabetes and smoking are frequently co-morbid conditions leading to arterial insufficiency, significantly increasing the risk of non-healing wounds and subsequent major amputation. Autologous patient-specific mesenchymal stem cells (MSCs) present a novel tool for regenerative therapy to treat advanced stages of arterial insufficiency. The regenerative performance of cells from diabetics with impaired arterial perfusion is known to be reduced, but the impact of additional patient factors such as smoking remains poorly understood. Approach: MSCs were harvested from amputees under IRB approval. Mitochondria were evaluated for mitophagy and bioenergetic function. MSC growth, reactive oxygen species (ROS), and synthetic function were measured. Exogenous nicotine was used to mimic smoking byproducts. Data were analyzed by one-way analysis of variance with p < 0.05 considered statistically significant. Results: Four MSC patient lines were from smokers and four were from non-smokers. All were male, diabetic, and matched for age. Mitochondrial turnover, ROS production, proliferation, and doubling time were comparable between groups. Smoking status significantly decreased glycolytic capacity, maximal mitochondrial respiration, and the synthetic function of MSCs compared with non-smokers (p < 0.05). Acute nicotine exposure in non-smoker MSCs significantly increased mitochondrial function, an effect that incompletely resolved with nicotine withdrawal (p < 0.001). Innovation: This study implicates mitochondrial dysfunction in smoking-mediated impairment of MSC synthetic function. Conclusion: Smoking alters mitochondrial bioenergetics and synthetic function of MSCs from diabetic patients with arterial insufficiency. Restoring mitochondrial function may improve synthetic function and therapeutic capabilities of smoker MSCs. Targeted rejuvenation strategies may be required based on smoking status for autologous MSC therapies for patients with arterial insufficiency.
