Sulfatide Inhibits HMGB1 Secretion by Hindering Toll-Like Receptor 4 Localization Within Lipid Rafts

The high mobility group box 1 (HMGB1) is a well-known late mediator of sepsis, secreted by multiple stimuli, involving pathways, such as the mitogen-activated protein kinase (MAPK) and nuclear factor kappa B (NF-κB) pathways, and reactive oxygen species (ROS) under inflammation. Sulfatide, in contrast, is a sphingolipid commonly found in myelin sheets with a disputed immunological role. We sought to determine the immunological characteristics of sulfatide in the periphery by analyzing the secretion of HMGB1 triggered by lipopolysaccharide (LPS) stimulation in Raw 264.7 cells. Suppression of HMGB1 secretion by inhibiting its cytosolic translocation was observed after pre-treatment with sulfatide before LPS stimulation. Further analysis of the downstream molecules of toll-like receptor (TLR) signaling revealed suppression of c-Jun N-terminal kinase (JNK) phosphorylation and p65 translocation. LPS-mediated ROS production was also decreased when sulfatide pre-treatment was provided, caused by the down-regulation of the phosphorylation of activators, such as IRAK4 and TBK1. Investigation of the upstream mechanism that encompasses all the aforementioned inhibitory characteristics unveiled the involvement of lipid rafts. In addition to the co-localization of biotinylated sulfatide and monosialotetrahexosylganglioside, a decrease in LPS-induced co-localization of TLR4 and lipid raft markers was observed when sulfatide treatment was given before LPS stimulation. Overall, sulfatide was found to exert its anti-inflammatory properties by hindering the co-localization of TLR4 and lipid rafts, nullifying the effect of LPS on TLR4 signaling. Similar effects of sulfatide were also confirmed in the LPS-mediated murine experimental sepsis model, showing decreased levels of serum HMGB1, increased survivability, and reduced pathological severity.ope

Canagliflozin protects against cisplatin-induced acute kidney injury by AMPK-mediated autophagy in renal proximal tubular cells

Sodium-glucose cotransporter 2 inhibitors, which are recently introduced as glucose-lowering agents, improve cardiovascular and renal outcomes in patients with diabetes mellitus. These drugs also have beneficial effects in various kidney disease models. However, the effect of SGLT2 inhibitors on cisplatin-induced acute kidney injury (AKI) and their mechanism of action need to be elucidated. In this study, we investigated whether canagliflozin protects against cisplatin-induced AKI, depending on adenosine monophosphate-activated protein kinase (AMPK) activation and following induction of autophagy. In the experiments using the HK-2 cell line, cell viability assay and molecular analysis revealed that canagliflozin protected renal proximal tubular cells from cisplatin, whereas addition of chloroquine or compound C abolished the protective effect of canagliflozin. In the mouse model of cisplatin-induced AKI, canagliflozin protected mice from cisplatin-induced AKI. However, treatment with chloroquine or compound C in addition to administration of cisplatin and canagliflozin eliminated the protective effect of canagliflozin. Collectively, these findings indicate that canagliflozin protects against cisplatin-induced AKI by activating AMPK and autophagy in renal proximal tubular cellsope

Association Between Systolic Blood Pressure Variability and Major Adverse Cardiovascular Events in Korean Patients With Chronic Kidney Disease: Findings From KNOW-CKD

Background Whether visit‐to‐visit systolic blood pressure (SBP) variability can predict major adverse cardiovascular events (MACE) in patients with chronic kidney disease is unclear. Methods and Results We investigated the relationship between SDs of visit‐to‐visit SBP variability during the first year of enrollment and MACE among 1575 participants from KNOW‐CKD (Korean Cohort Study for Outcome in Patients With Chronic Kidney Disease). Participants were categorized into 3 groups according to tertiles of visit‐to‐visit SBP variability (SD). The study end point was MACE, defined as a composite of nonfatal myocardial infarction, unstable angina, revascularization, nonfatal stroke, hospitalization for heart failure, or cardiac death. During 6748 patient‐years of follow‐up (median, 4.2 years), MACE occurred in 64 participants (4.1%). Compared with the lowest tertile of visit‐to‐visit SBP variability (SD), the hazard ratios (HRs) for the middle and the highest tertile were 1.64 (95% CI, 0.80–3.36) and 2.23 (95% CI, 1.12–4.44), respectively, in a multivariable cause‐specific hazard model. In addition, the HR associated with each 5‐mm Hg increase in visit‐to‐visit SBP variability (SD) was 1.21 (95% CI, 1.01–1.45). This association was consistent in sensitivity analyses with 2 additional definitions of SBP variability determined by the coefficient of variation and variation independent of the mean. The corresponding HRs for the middle and highest tertiles were 2.11 (95% CI, 1.03–4.35) and 2.28 (95% CI, 1.12–4.63), respectively, in the analysis with the coefficient of variation and 1.76 (95% CI, 0.87–3.57) and 2.04 (95% CI, 1.03–4.03), respectively, with the variation independent of the mean. Conclusions Higher visit‐to‐visit SBP variability is associated with an increased risk of MACE in patients with chronic kidney disease.ope

Hyponatremia Predicts New-Onset Cardiovascular Events in Peritoneal Dialysis Patients

BACKGROUND AND AIM: Cardiovascular (CV) disease is the leading cause of morbidity and mortality in patients on peritoneal dialysis (PD). Hyponatremia was recently shown to be a modifiable factor that is strongly associated with increased mortality in PD patients. However, the clinical impact of hyponatremia on CV outcomes in these patients is unclear. METHODS: To determine whether a low serum sodium level predicts the development of CV disease, we carried out a prospective observational study of 441 incident patients who started PD between January 2000 and December 2005. Time-averaged serum sodium (TA-Na) levels were determined to investigate the ability of hyponatremia to predict newly developed CV events in these patients. RESULTS: During a mean follow-up of 43.2 months, 106 (24.0%) patients developed new CV events. The cumulative incidence of new-onset CV events after the initiation of PD was significantly higher in patients with TA-Na levels ≤ 138 mEq/L than in those with a TA-Na > 138 mEq/L. After adjustment for multiple potentially confounding covariates, an increase in TA-Na level was found to be associated with a significantly lower risk of CV events (subdistribution hazard ratio per 1 mEq/L increase, 0.90; 95% confidence interval, 0.83-0.96; p = 0.003). Patients with a TA-Na ≤ 138 mEq/L had a 2.31-fold higher risk of suffering a CV event. CONCLUSIONS: These results provide evidence of a clear association between low serum sodium and new-onset CV events after dialysis initiation in PD patients. Whether the correction of hyponatremia for this indication provides additional protection for the development of CV disease in these patients remains to be addressed in interventional studies.ope

Low Serum Bicarbonate Predicts Residual Renal Function Loss in Peritoneal Dialysis Patients

Low residual renal function (RRF) and serum bicarbonate are associated with adverse outcomes in peritoneal dialysis (PD) patients. However, a relationship between the 2 has not yet been determined in these patients. Therefore, this study aimed to investigate whether low serum bicarbonate has a deteriorating effect on RRF in PD patients.This prospective observational study included a total of 405 incident patients who started PD between January 2000 and December 2005. We determined risk factors for complete loss of RRF using competing risk methods and evaluated the effects of time-averaged serum bicarbonate (TA-Bic) on the decline of RRF over the first 3 years of dialysis treatment using generalized linear mixed models.During the first 3 years of dialysis, 95 (23.5%) patients became anuric. The mean time until patients became anuric was 20.8 ± 9.0 months. After adjusting for multiple potentially confounding covariates, an increase in TA-Bic level was associated with a significantly decreased risk of loss of RRF (hazard ratio per 1 mEq/L increase, 0.84; 0.75-0.93; P = 0.002), and in comparison to TA-Bic ≥ 24 mEq/L, TA-Bic < 24 mEq/L conferred a 2.62-fold higher risk of becoming anuric. Furthermore, the rate of RRF decline estimated by generalized linear mixed models was significantly greater in patients with TA-Bic < 24 mEq/L compared with those with TA-Bic ≥ 24 mEq/L (-0.16 vs -0.11 mL/min/mo/1.73 m, P < 0.001).In this study, a clear association was found between low serum bicarbonate and loss of RRF in PD patients. Nevertheless, whether correction of metabolic acidosis for this indication provides additional protection for preserving RRF in these patients is unknown. Future interventional studies should more appropriately address this question.ope

전고상 박막 리튬 폴리머 전지를 위한 스핀 코팅된 폴리머 전해질

Thesis(doctor`s)--서울대학교 대학원 :재료공학부,2006.Docto

고온 필라멘트 화학증착법에 의한 카본나노튜브 성장에 자기장이 미치는 영향

학위논문(석사)--서울대학교 대학원 :재료공학부,2002.Maste

컴퓨터 통신을 이용한 과학 토론 학습에서 상호작용의 증진을 위한 체제 구축

학위논문(석사)--서울대학교 대학원 :과학교육과 물리전공,1997.Maste

상대운동의 과제 중심 학습을 위한 웹 기반 환경 개발

Thesis (doctoral)--서울대학교 대학원 :과학교육과 물리 전공,2001.Docto

Canagliflozin의 신장 근위세뇨관 세포 AMPK 매개 자가포식 활성화에 의한 cisplatin 유발 급성신손상에 대한 보호효과

prohibition박