Role of Aldosterone in Oxidative Stress and Renal Injury

Autophagosome protects proximal tubular cells from aldosterone-induced senescence through improving oxidative stress

Aldosterone exerts an enormous function on proximal tubular cells (PTC) senescence, which is a common pathomechanism contributing to renal dysfunction. Numerous studies have shown that oxidative stress is deeply involved in the pathophysiologic processes of chronic kidney diseases. The study aims to investigate whether autophagy could regulate the process of senescence through oxidative stress in PTC both in vivo and ex vivo. Our results suggested that aldosterone treatment increased the senescence and oxidative stress as evidenced by increased percent of SA-β-Gal positive cells, reactive oxygen species level, expression of NADPH oxidase 4 (NOX4) rather than NOX2, and the up-regulation of p21 in cultured PTC. Furthermore, the alternation of the expression of p62 and LC3-II/LC3-I demonstrated that aldosterone treatment remarkably influenced autophagic flux. NOX4 siRNA treatment or autophagy induction with rapamycin reduced the oxidative stress and senescence in aldosterone-induced PTC. On the contrary, inhibition of autophagy with chloroquine worsened these changes. Similar results were further confirmed in vivo. Our results suggested that autophagy may become a realistic therapeutic strategy against aldosterone-induced PTC injury via improving oxidative stress.

Remifentanil temporarily improves renal function in adult patients with chronic kidney disease undergoing orthopedic surgery

PURPOSE

The objective of this study was to confirm the renal protective effect of remifentanil-based anesthesia in perioperative adult patients with chronic kidney disease (CKD).

METHODS

A total of 90 non-dialysis perioperative adult patients with CKD, with preoperative estimated glomerular filtration rate from creatinine (eGFRcreat) values of lower than 50 ml/min/1.73 m(2), who had undergone orthopedic surgery under general anesthesia were retrospectively selected. The subjects were divided into two groups according to whether or not remifentanil was used for anesthesia management: group R, in which remifentanil was used for anesthesia management (n = 45), and group NR, in which remifentanil was not used for anesthesia (n = 45). eGFRcreat was measured pre-surgery (pre), 7 days after surgery (day-7), and 14 days after surgery (day-14).

RESULTS

In group R, both day-7 eGFRcreat (52.2 ± 17.0 ml/min/1.73 m(2)) and day-14 eGFRcreat (49.7 ± 15.5 ml/min/1.73 m(2)) were significantly higher than the pre eGFRcreat (40.7 ± 7.5 ml/min/1.73 m(2)) (day-7: p < 0.01; day-14: p < 0.01). In group NR, on the other hand, pre eGFRcreat (37.8 ± 7.6 ml/min/1.73 m(2)), day-7 eGFRcreat (41.2 ± 10.9 ml/min/1.73 m(2)), and day-14 eGFRcreat (40.2 ± 10.5 ml/min/1.73 m(2)) values were similar. Furthermore, both day-7 eGFRcreat and day-14 eGFRcreat were significantly higher in group R than in group NR (day-7: p < 0.01; day-14: p < 0.01).

CONCLUSIONS

Our findings suggest that anesthesia management using remifentanil may have a renal protective effect in perioperative adult CKD patients undergoing orthopedic surgery.