Thymosin Beta 4 Prevents Oxidative Stress by Targeting Antioxidant and Anti-Apoptotic Genes in Cardiac Fibroblasts

Thymosin beta-4 (Tβ4) is a ubiquitous protein with diverse functions relating to cell proliferation and differentiation that promotes wound healing and modulates inflammatory responses. The effecter molecules targeted by Tβ4 for cardiac protection remains unknown. The purpose of this study is to determine the molecules targeted by Tβ4 that mediate cardio-protection under oxidative stress.Rat neonatal fibroblasts cells were exposed to hydrogen peroxide (H(2)O(2)) in presence and absence of Tβ4 and expression of antioxidant, apoptotic and pro-fibrotic genes was evaluated by quantitative real-time PCR and western blotting. Reactive oxygen species (ROS) levels were estimated by DCF-DA using fluorescent microscopy and fluorimetry. Selected antioxidant and antiapoptotic genes were silenced by siRNA transfections in cardiac fibroblasts and the effect of Tβ4 on H(2)O(2)-induced profibrotic events was evaluated.Pre-treatment with Tβ4 resulted in reduction of the intracellular ROS levels induced by H(2)O(2) in the cardiac fibroblasts. This was associated with an increased expression of antioxidant enzymes Cu/Zn superoxide dismutase (SOD) and catalase and reduction of Bax/Bcl(2) ratio. Tβ4 treatment reduced the expression of pro-fibrotic genes [connective tissue growth factor (CTGF), collagen type-1 (Col-I) and collagen type-3 (Col-III)] in the cardiac fibroblasts. Silencing of Cu/Zn-SOD and catalase gene triggered apoptotic cell death in the cardiac fibroblasts, which was prevented by treatment with Tβ4.This is the first report that exhibits the targeted molecules modulated by Tβ4 under oxidative stress utilizing the cardiac fibroblasts. Tβ4 treatment prevented the profibrotic gene expression in the in vitro settings. Our findings indicate that Tβ4 selectively targets and upregulates catalase, Cu/Zn-SOD and Bcl(2), thereby, preventing H(2)O(2)-induced profibrotic changes in the myocardium. Further studies are warranted to elucidate the signaling pathways involved in the cardio-protection afforded by Tβ4

Journal of Clinical Nephrology The Risk-Adjusted Impact of Intraoperative Hemofi ltration on Real-World Outcomes of Patients Undergoing Cardiac Surgery

ABSTRACT Objectives: The role of perioperative hemofi ltration (HF) in adult patients with impaired renal function undergoing cardiac surgery is controversial. There are suggestions that it may be benefi cial for high risk patients undergoing prolonged cardiopulmonary bypass (CPB) surgery. However, long term outcomes in coronary artery bypass graft (CABG) surgery patients have not been investigated. Methods: To address this we retrospectively followed 7620 patients who underwent CABG between April 2001 and March 2006. Logistic regression was used to risk adjust in-hospital outcomes. Cox proportional hazards analysis was used to risk adjust Kaplan-Meier freedom from death curves. Outcomes were adjusted for American Heart Association and American College of College of Cardiology recommended variables. Results: 113 patients had intraoperative HF, 38 had postoperative HF and control group of 7006 that had no HF. After adjusting for differences in case-mix, patients with preoperative kidney disease who received postoperative HF proportionately had signifi cantly higher rates of hospital deaths as compared with intraoperative HF patients. In addition, 5-year follow-up risk-adjusted freedom from death indicated signifi cant differences between intraoperative HF group and postoperative HF patients. Conclusions: These fi ndings support the hypothesis that after adjusting for differences in case mixes, the use of intraoperative hemofi ltration may offer superior short term clinical outcomes and longer-term survival benefi ts for patients with preoperative kidney disease

The Risk-Adjusted Impact of Intraoperative Hemofiltration on Real-World Outcomes of Patients Undergoing Cardiac Surgery

Objectives: The role of perioperative hemofiltration (HF) in adult patients with impaired renal function undergoing cardiac surgery is controversial. There are suggestions that it may be beneficial for high risk patients undergoing prolonged cardiopulmonary bypass (CPB) surgery. However, long term outcomes in coronary artery bypass graft (CABG) surgery patients have not been investigated. Methods: To address this we retrospectively followed 7620 patients who underwent CABG between April 2001 and March 2006. Logistic regression was used to risk adjust in-hospital outcomes. Cox proportional hazards analysis was used to risk adjust Kaplan-Meier freedom from death curves. Outcomes were adjusted for American Heart Association and American College of College of Cardiology recommended variables. Results: 113 patients had intraoperative HF, 38 had postoperative HF and control group of 7006 that had no HF. After adjusting for differences in case-mix, patients with preoperative kidney disease who received postoperative HF proportionately had significantly higher rates of hospital deaths as compared with intraoperative HF patients. In addition, 5-year follow-up risk-adjusted freedom from death indicated significant differences between intraoperative HF group and postoperative HF patients. Conclusions: These findings support the hypothesis that after adjusting for differences in case mixes, the use of intraoperative hemofiltration may offer superior short term clinical outcomes and longer-term survival benefits for patients with preoperative kidney disease

Electroencephalographic changes after pediatric cardiac surgery with cardiopulmonary bypass: is slow wave activity unfavorable?

Pediatric cardiac surgery with cardiopulmonary bypass (CPB) is frequently associated with neurologic deficits. We describe the postoperative EEG changes, assess their possible causes, and evaluate their relevance to neurologic outcome. Thirty-one children and five neonates with congenital heart disease were included. EEG recording started after intubation and continued until 22-96 h after CPB. In addition to conventional analysis, spectral analysis was performed for occipital and frontal electrodes, and differences between pre- and postoperative delta power (delta-deltaP) were calculated. Maximum values of occipital delta-deltaP that occurred within 48 h after CPB were correlated with clinical variables and with perioperative markers of oxidative stress and inflammation. Occipital delta-deltaP correlated with frontal delta-deltaP, and maximum delta-deltaP correlated with conventional rating. Distinct rise of deltaP was detected in 18 of 21 children without any acute or long-term neurologic deficits but only in five of 10 children with temporary or permanent neurologic deficits. Furthermore, maximally registered delta-deltaP was inversely associated with duration of CPB and postoperative ventilation. Maximal delta-deltaP was also inversely associated with the loss of plasma ascorbate (as an index of oxidative stress) and plasma levels of IL-6 and IL-8. Slow wave activity frequently occurs within 48 h after CPB. However, our data do not support the notion that EEG slowing is associated with adverse neurologic outcome. This is supported by the fact that EEG slowing was associated with less oxido-inflammatory stress