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Daejeon, South Korea

Choi D.E.,Chungnam National University | Jeong J.Y.,Chungnam National University | Lim B.J.,Daejeon St. Mary Hospital | Chang Y.-K.,Yonsei University | And 3 more authors.
Journal of Urology | Year: 2011

Purpose: Renin-angiotensin system activation is involved in inflammation and fibrosis in the kidney. Aliskiren, a direct renin inhibitor, decreases renin-angiotensin system activation, including plasma renin activity and angiotensin II, but increases the prorenin level, which may promote inflammation and fibrosis in renal tissue. Thus, we evaluated whether inhibiting the renin-angiotensin system by aliskiren would decrease renal inflammation and fibrosis in a mouse model of unilateral ureteral obstruction. Materials and Methods: Ten-week-old male C57BL/6 mice (Samtako, Kyoung Gi-Do, Korea) weighing 30 to 33 gm were divided into 4 groups, including vehicle or aliskiren treated sham operated and vehicle or aliskiren treated unilateral ureteral obstruction groups. We evaluated plasma renin activity, and plasma renin and renal mRNA expression levels of renin and (pro)renin receptor. To evaluate inflammation and fibrosis renal mRNA expression of monocyte chemotactic protein-1, osteopontin and transforming growth factor-β was measured. Hematoxylin and eosin, Masson's trichrome staining, and immunohistochemical staining for CD68, transforming growth factor-β and α-smooth muscle actin were performed. Results: Plasma renin activity was significantly lower in the aliskiren treated obstruction group than in the vehicle treated obstruction group. Aliskiren treatment increased renal mRNA expression of renin. The number of CD68 positive cells, and renal monocyte chemotactic protein-1 and osteopontin mRNA levels were significantly higher in mice with unilateral ureteral obstruction than in sham operated mice. Aliskiren decreased the increased levels of these inflammation markers. Aliskiren also decreased renal transforming growth factor-β mRNA expression, transforming growth factor-β and α-smooth muscle actin immunostaining, and Masson's trichrome stained areas of unilateral ureteral obstruction kidneys. Conclusions: Aliskiren has anti-inflammatory and antifibrotic effects in an experimental unilateral ureteral obstruction mouse model. © 2011 American Urological Association Education and Research, Inc. Source


Lim B.J.,Chungnam National University | Jeong J.Y.,Chungnam National University | Chang Y.-K.,Daejeon St. Mary Hospital | Na K.-R.,Chungnam National University | And 3 more authors.
Renal Failure | Year: 2012

Although cisplatin is a highly effective antineoplastic agent, nephrotoxicity is its major clinical problem. Recently, it was reported that Spirulina, a blue-green algae, has potent antioxidant properties. The aim of this study was to establish the possible protective role of C-phycocyanin (PC), one of the active ingredients of Spirulina, against cisplatin-induced nephrotoxicity. This study was carried out using human kidney-2 (HK-2) cells and male C57BL6 mice. Cells and mice were divided into four groups; untreated control group, PC-treated control group, cisplatin-treated group, and PC plus cisplatin-treated group. The molecular, functional, and structural parameters were measured. PC significantly attenuated blood urea nitrogen, serum creatinine, renal histological damages, and apoptotic cell death in cisplatin-treated mice. The cisplatin-induced cell death was significantly attenuated in cells pretreated with PC. PC also significantly attenuated the elevation of p-ERK, p-JNK, and p-p38 induced by cisplatin treatment. The expression of Bax, caspase-9, and caspase-3 in cisplatin-treated cells were also decreased by PC treatment. In conclusion, PC ameliorates cisplatin-induced nephrotoxicity and, at least in part, suppression of p-ERK, p-JNK, p-p38, Bax, caspase-9, and caspase-3 may be involved in this mechanism. © 2012 Informa Healthcare USA, Inc. Source


Chang Y.-K.,Daejeon St. Mary Hospital | Chang Y.-K.,Catholic University of Korea | Choi H.,Clinical Research Institute | Jeong J.Y.,Chungnam National University | And 4 more authors.
PLoS ONE | Year: 2016

Dapagliflozin, a new type of drug used to treat diabetes mellitus (DM), is a sodium/glucose cotransporter 2 (SGLT2) inhibitor. Although some studies showed that SGLT2 inhibition attenuated reactive oxygen generation in diabetic kidney the role of SGLT2 inhibition is unknown. We evaluated whether SLT2 inhibition has renoprotective effects in ischemiareperfusion (IR) models. We evaluated whether dapagliflozin reduces renal damage in IR mice model. In addition, hypoxic HK2 cells were treated with or without SGLT2 inhibitor to investigate cell survival, the apoptosis signal pathway, and the induction of hypoxia-inducible factor 1 (HIF1) and associated proteins. Dapagliflozin improved renal function. Dapagliflozin reduced renal expression of Bax, renal tubule injury and TUNEL-positive cells and increased renal expression of HIF1 in IR-injured mice. HIF1 inhibition by albendazole negated the renoprotective effects of dapagliflozin treatment in IR-injured mice. In vitro, dapagliflozin increased the expression of HIF1, AMP-activated protein kinase (AMPK), and ERK and increased cell survival of hypoxic HK2 cells in a dose-dependent manner. In conclusion, dapagliflozin attenuates renal IR injury. HIF1 induction by dapagliflozin may play a role in renoprotection against renal IR injury. © 2016 Chang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Source


Suh G.-H.,Hallym University | Ryu S.-H.,Konkuk University | Lee D.-W.,Inje University | Han C.,Korea University | And 12 more authors.
American Journal of Geriatric Psychiatry | Year: 2011

Objective: This study aims to examine survival of patients with Alzheimer disease (AD) receiving clinical efficacy of cholinesterase inhibitors (ChEIs) and to compare their survival with those of patients with AD who never received ChEIs and cogni- tively intact old psychiatric outpatients. Design, setting, and Participants: The retrospective cohort study used national mortality data provided by the Korean National Statistics Office and electronic database of 15 general hospitals on older patients who began outpatient treatment with psychiatric medications including ChEIs (N = 3,813). The authors controlled for confounding by using multivariate models and propensity scoring methods. Measurements: Mortality rate of patients with AD receiving ChEIs was compared with those of patients with AD who never received ChEIs and cognitively intact old psychiatric outpatients. Results: Observed additional survival of patients with AD receiving ChEIs (mortality rate: 13.1%), when compared with patients with AD who never received ChEIs (15.4%) was not statistically significant (p = 0.74; hazard ratio [HR]: 1.03, 95% confidence interval [CI]: 0.67-1.59). Patients with AD receiving ChEIs showed higher mortality rate (13.1%) compared with that of cognitively intact old psychiatric outpatients (8.6%) (p <0.001; HR: 1.60, 95% CI: 0.96-2.68). Conclusion: This study does not support that ChEIs increase survival of patients with AD, compared with patients with AD who have never treated with ChEIs. Therefore, all ChEIs should be considered for symptomatic use only and not to be capable of modifying mortality of patients with AD. © 2011 American Association for Geriatric Psychiatry. Source


Chang Y.-K.,Daejeon St. Mary Hospital | Choi H.,Daejeon St. Mary Hospital | Jeong J.Y.,Daejeon St. Mary Hospital | Na K.-R.,Daejeon St. Mary Hospital | And 2 more authors.
Kidney and Blood Pressure Research | Year: 2016

Background/Aims: Both endothelin-1 (ET-1) and the renin-angiotensin system (RAS) may play important roles in renal fibrosis in the obstructed kidney. However, there have been few clear demonstrations of a relationship between their activation and additive or synergistic roles in renal fibrosis. We investigated the protective roles and relationship between renal RAS and ET-1 in unilateral ureteral obstruction (UUO) mice. Methods: 8-week-old male C57BL/6 mice were divided into seven groups: sham, bosentan+sham, valsartan+sham, vehicle+UUO, bosentan+UUO, valsartan+UUO, and valsartan+bosentan+UUO. Valsartan and bosentan were administered orally using an NG tube (valsartan 10 mg/kg/day, bosentan 100 mg/kg/day for 8 days, after which the molecular and structural kidney parameters were evaluated. Bosentan treatment elevated plasma renin activity, renal renin, and AT1R expression in UUO mice. Results: Although valsartan decreased plasma ET-1 in these mice, it did not affect ET(A) or ET(B) in their kidneys. Co-treatment with valsartan and bosentan decreased ET-1 in these mice compared to the single treatments. Bosentan, but not valsartan, elevated eNOS expression in their kidneys. Co-treatment with valsartan and bosentan reduced TGF-β, α-SMA, and collagen IV expression, and the Masson's trichrome stained area in their kidneys. Conclusions: Bosentan and valsartan acted complementarily, and co-treatment with both drugs had an additive protective effect against renal fibrosis. © 2016 The Author(s) Published by S. Karger AG, Basel Source

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