RT Journal Article SR Electronic T1 Evidence for a hyper-reductive redox in a sub-set of heart failure patients JF bioRxiv FD Cold Spring Harbor Laboratory SP 246413 DO 10.1101/246413 A1 Sairam Thiagarajan A1 Amit N. Patel A1 Meenu Subrahmanian A1 Rajendran Gopalan A1 Steven M. Pogwizd A1 Sudha Ramalingam A1 Sankaran Ramalingam A1 Namakkal S. Rajasekaran YR 2018 UL http://biorxiv.org/content/early/2018/01/11/246413.abstract AB Background Oxidative stress has been linked to heart failure (HF) in humans. Antioxidant-based treatments are often ineffective. Therefore, we hypothesize that some of the HF patients might have a reductive stress (RS) condition. Investigating RS-related mechanisms will aid in personalized optimization of redox homeostasis for better outcomes among HF patients.Methods Blood samples were collected from HF patients (n=54) and healthy controls (n=42) and serum was immediately preserved in –80°C for redox analysis. Malondialdehyde (MDA; lipid peroxidation) levels by HPLC, reduced glutathione (GSH) and its redox ratio (GSH/GSSG) using enzymatic-recycling assay in the serum of HF patients were measured. Further, the kinetics of key enzymatic-antioxidant enzymes was analyzed by UV-Vis spectrophotometry. Non-invasive echocardiography was used to relate circulating redox status with cardiac function and remodeling.Results The circulatory redox state (GSH/MDA ratio) was used to stratify the HF patients into normal redox (NR), hyper-oxidative (HO), and hyper-reductive (HR) groups. While the majority of the HF patients exhibited the HO (42%), 41% of them had a normal redox (NR) state. Surprisingly, a subset of HF patients (17%) belonged to the hyper-reductive group, suggesting a strong implication for RS in the progression of HF. In HF patients, SOD, GPx and catalase were significantly increased while GR activity was significantly reduced relative to healthy controls. Furthermore, echocardiography analyses revealed that 55% of HO patients had higher systolic dysfunction while 75% of the hyper-reductive patients had higher diastolic dysfunction.Conclusion These results suggest that RS may be associated with HF pathogenesis for a subset of cardiac patients. Thus, stratification of HF patients based on their circulating redox status may serve as a useful prognostic tool to guide clinicians designing personalized antioxidant therapies.