• The Korean Journal of Physiology and Pharmacology
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• v.25 no.2
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• pp.139-146
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• 2021

Mitochondrial NADP+-dependent isocitrate dehydrogenase 2 (IDH2) produces NADPH, which is known to inhibit mitochondrial oxidative stress. Ureteral obstruction induces kidney inflammation and fibrosis via oxidative stress. Here, we investigated the role and underlying mechanism of IDH2 in unilateral ureteral obstruction (UUO)-induced kidney inflammation using IDH2 gene deleted mice (IDH2-/-). Eight- to 10-week-old female IDH2-/- mice and wild type (IDH2+/+) littermates were subjected to UUO and kidneys were harvested 5 days after UUO. IDH2 was not detected in the kidneys of IDH2-/- mice, while UUO decreased IDH2 in IDH2+/+ mice. UUO increased the expressions of markers of oxidative stress in both IDH2+/+ and IDH2-/- mice, and these changes were greater in IDH2-/- mice compared to IDH2+/+ mice. Bone marrow-derived macrophages of IDH2-/- mice showed a more migrating phenotype with greater ruffle formation and Rac1 distribution than that of IDH2+/+ mice. Correspondently, UUO-induced infiltration of monocytes/macrophages was greater in IDH2-/- mice compared to IDH2+/+ mice. Taken together, these data demonstrate that IDH2 plays a protective role against UUO-induced inflammation through inhibition of oxidative stress and macrophage infiltration.

• Herbal Formula Science
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• v.31 no.3
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• pp.133-144
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• 2023

Ureteral obstruction can be causes of renal dysfunction and renal injury at late period of kidney pathology. The purpose of this study was to determine the protective effects of Oryeongsan (ORS), Geumgwe-sinkihwan (GSH), and Jwagwieum (JGE) in rats with unilateral ureteral obstruction (UUO). The animal models were divided into five groups randomly at the age of 5 weeks; Control group: SD male rats (n=10), UUO group: SD male rats with UUO surgery (n=10), ORS group: SD male rats with UUO surgery + ORS 200 mg/kg/day (n=10), GSH group: SD male rats with UUO surgery + GSH 200 mg/kg/day (n=10), JGE group: SD male rats with UUO surgery + JGE 200 mg/kg/day (n=10). Treatment with ORS, GSH, and JGE significantly ameliorate creatinine clearance(Ccr). The present results also showed that ORS, GSH, and JGE improved the morphological aspects of renal tissues. These prescriptions also reduced the expression levels of cytokines such as TNF-α, IL-1β, and IL-6. In Kidney, UUO increased the expression levels of inflamasome markers such as NLRP3, ASC, and Caspase-1. However, ORS, GSH, and JGE suppressed these levele. Treatment with these prescriptions reduced kidney inflammation markers such as Neutrophil Gelatinase Associated Lipocalin (NGAL) and kidney injury molecule -1 (KIM-1). Therefore, these findings suggest that ORS, GSH, and JGE has a protective effect on renal injury by alleviating renal inflammation and improving renal function in rats with UUO.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.1
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• pp.55-63
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• 1997

The present study was designed to quantify the alterations of renal renin, angiotensin type I receptor ($AT_1$), $TGF-{\beta}1$, and fibronectin gene expression in rats with unilateral ureteral obstruction (UUO). We also investigated the change of $AT_1$ density during UUO. Reverse transcription-polymerase chain reaction (RT-PCR) technique and receptor binding assay were used to detect mRNA expression and receptor density, respectively. At one day after UUO, renin mRNA level of the obstructed kidneys was decreased transiently and then subsequently increased to the level of sham kidneys. In the contralateral kidneys of the same rats, on the contrary, renin mRNA level was gradually decreased. Then, at 9 days after UUO, it was significantly lower than that of sham kidneys. The expressions of both $AT_1$ subtypes, called $AT_{1A}$ and $AT_{1B}$, mRNAs did not change at any time. UUO led to a significant decrease in $AT_1$ density in the obstructed kidneys compared with the sham kidneys at 1 and 3 days $(66\;{\pm}\;11.6%\;(p<0.005)\;and\;73\;{\pm}\;4.0%$ (p<0.01), respectively). Thereafter, $AT_1$ density was gradually increased and at 9 days it showed a marked elevation in the obstructed kidneys compared to the sham kidneys. In contrast, in the contralateral kidneys $AT_1$ density was significantly reduced from 3 to 9 days after UUO. The $TGF-{\beta}$1 mRNA level of the obstructed kidneys was unexpectedly decreased at 6 days after UUO. Then, at 9 days it was followed by a significant increase in the obstructed kidneys, whereas it showed an obvious decrease in the contralateral kidneys. In addition, fibronectin mRNA level was also significantly increased in the obstructed kidneys after UUO compared to the sham or the contralateral kidneys of the same rats. These results suggest a differential regulation of renal renin, $AT_1$ receptor, $TGF-{\beta}$1 and fibronectin mRNA levels at different stages of UUO.

• Biomolecules & Therapeutics
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• v.29 no.1
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• pp.41-51
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• 2021

Src family kinases (SFKs), an important group of non-receptor tyrosine kinases, are suggested to be excessively activated during various types of tissue fibrosis. The present study investigated the effect of KF-1607, an orally active and a newly synthesized Src kinase inhibitor (SKI) with proposed low toxicity, in preventing the progression of renal interstitial fibrosis. Unilateral ureteral obstruction (UUO) surgery was performed in 6-week-old male C57BL/6 mice to induce renal interstitial fibrosis. Either KF-1607 (30 mg/kg, oral gavage) or PP2 (2 mg/kg, intraperitoneal injection), a common experimental SKI, was administered to mice for seven days, started one day prior to surgery. UUO injury-induced SFK expression, including Src, Fyn, and Lyn kinase. SFK inhibition by KF-1607 prevented the progression of tubular injury in UUO mice, as indicated by decreases in albuminuria, urinary KIM-1 excretion, and kidney NGAL protein expression. Renal tubulointerstitial fibrosis was attenuated in response to KF-1607, as shown by decreases in α-SMA, collagen I and IV protein expression, along with reduced Masson's trichrome and collagen-I staining in kidneys. KF-1607 also inhibited inflammation in the UUO kidney, as exhibited by reductions in F4/80 positive-staining and protein expression of p-NFκB and ICAM. Importantly, the observed effects of KF-1607 were similar to those of PP2. A new pan Src kinase inhibitor, KF-1607, is a potential pharmaceutical agent to prevent the progression of renal interstitial fibrosis.

• Korean Journal of Radiology
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• v.21 no.5
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• pp.588-597
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• 2020

Objective: To investigate the value of combined chemical exchange saturation transfer (CEST) and conventional magnetization transfer imaging (MT) in detecting metabolic and structural changes of renal fibrosis in rats with unilateral ureteral obstruction (UUO) at 3T MRI. Materials and Methods: Thirty-five Sprague-Dawley rats underwent UUO surgery (n = 25) or sham surgery (n = 10). The obstructed and contralateral kidneys were evaluated on days 1, 3, 5, and 7 after surgery. After CEST and MT examinations, ¹⁸F-labeled fluoro-2-deoxyglucose positron emission tomography was performed to quantify glucose metabolism. Fibrosis was measured by histology and western blots. Correlations were compared between asymmetrical magnetization transfer ratio at 1.2 ppm (MTR_asym(1.2ppm)) derived from CEST and maximum standard uptake value (SUV_max) and between magnetization transfer ratio (MTR) derived from MT and alpha-smooth muscle actin (α-SMA). Results: On days 3 and 7, MTR_asym(1.2ppm) and MTR of UUO renal cortex and medulla were significantly different from those of contralateral kidneys (p < 0.05). On day 7, MTR_asym(1.2ppm) and MTR of UUO renal cortex and medulla were significantly different from those of sham-operated kidneys (p < 0.05). The MTR_asym(1.2ppm) of UUO renal medulla was fairly negatively correlated with SUV_max (r = -0.350, p = 0.021), whereas MTR of UUO renal medulla was strongly negatively correlated with α-SMA (r = -0.744, p < 0.001). Conclusion: CEST and MT could provide metabolic and structural information for comprehensive assessment of renal fibrosis in UUO rats in 3T MRI and may aid in clinical monitoring of renal fibrosis in patients with chronic kidney disease.

• BMB Reports
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• v.53 no.11
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• pp.594-599
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• 2020

Lin28a has diverse functions including regulation of cancer, reprogramming and regeneration, but whether it promotes injury or is a protective reaction to renal injury is unknown. We studied how Lin28a acts in unilateral ureteral obstruction (UUO)-induced renal fibrosis following unilateral ureteral obstruction, in a mouse model. We further defined the role of Lin28a in transforming growth factor (TGF)-signaling pathways in renal fibrosis through in vitro study using human tubular epithelium-like HK-2 cells. In the mouse unilateral ureteral obstruction model, obstruction markedly decreased the expression of Lin28a, increased the expression of renal fibrotic markers such as type I collagen, α-SMA, vimentin and fibronectin. In TGF-β-stimulated HK-2 cells, the expression of Lin28a was reduced and the expression of renal fibrotic markers such as type I collagen, α-SMA, vimentin and fibronectin was increased. Adenovirus-mediated overexpression of Lin28a inhibited the expression of TGF-β-stimulated type I collagen, α-SMA, vimentin and fibronectin. Lin28a inhibited TGF-β-stimulated SMAD3 activity, via inhibition of SMAD3 phosphorylation, but not the MAPK pathway ERK, JNK or p38. Lin28a attenuates renal fibrosis in obstructive nephropathy, making its mechanism a possible therapeutic target for chronic kidney disease.

• The Journal of Korean Medicine
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• v.39 no.2
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• pp.1-12
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• 2018

Objectives: The objective of this study is to develop a new animal model with Kidney-hypofunction for Sasang Constitutional Medicine, especially for partial Soyangin(one of four constitution which has good digestive function and poor renal function) by Unilateral Ureteral Obstruction, and to estimate the factor related to obesity, dyslipidemia, and metabolic syndrome. Methods: The C57BL/6J mice were divided into 3 groups : normal group, high fat diet(HFD) control group, and HFD group with Unilateral Ureteral Obstruction(UUO). Then, the HFD control group and the experimental group were fed with high fat diet for 6 weeks. Food intake and body weight were measured at regular time by week. After the final experiment, blood was gathered for bloodchemical examination and organs(liver, fatty tissue) were remoed, weighted, and mRNA was analyzed with real-time PCR. Results: The weight growth rate with High fat diet went down by 8.35% in experimental group and had similar FER with the normal group, while HFD control group had higher weight growth rate and FER than any other groups. Also The experimental group had lower triglyceride and LDL cholesterol rate and higher glucose rate in serum. and in mRNA expression, GLUT-9, the protein related to excretion of uric acid and metabolic syndrome, expressed lower rate than that of HFD control group. and IL-6, a kind of cytokine related to obesity and metabolic syndrome, expressed more than HFD control group. Conclusions: It was found that Kidney-hypofunction animal-experimental model is susceptible to metabolic syndrome.

• Childhood Kidney Diseases
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• v.15 no.2
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• pp.125-137
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• 2011

Purpose : Men are generally more prone to chronic renal disease and progression to end stage renal disease than women. The purpose of this study is to prove the effect of gender and sex hormone on renal fibrosis in mice with unilateral ureteral obstruction (UUO) and to elucidate the specific underlying mechanisms. Methods :We compared the expression of ${\alpha}$-smooth muscle actin (${\alpha}$-SMA) in female and male mice with complete UUO (day 7). After this, we estimated the changes of renal fibrosis in the female mice with oophorectomy and in the female mice with oophorectomy and replacement of $17{\beta}$-estradiol, respectively. Results : The level of ${\alpha}$-SMA in the female kidney with UUO was significantly lower than that in the male kidney with UUO. oophorectomy and replacement of $17{\beta}$-estradiol did not change the expression of angiotensin II type 1 (AT1) receptor in the female kidney with UUO, whereas the expression of angiotensin II type 2 (AT2) receptor was significantly more elevated in the intact female (IF) and the oophorectomized female with estrogen (OF+E) than that in the oophorectomized female (OF). The expressions of inducible nitric oxide synthase (iNOS) in the IF and OF+E mice were significantly more elevated than that in the OF mice, which was similar to the expression of AT2 receptor. Conclusion : The female gender is associated with resistance to renal fibrosis in obstructive uropathy and this gender difference may originate from the existence of $17{\beta}$-estradiol, which has an anti-fibrotic effect via upregulation of the AT2 receptor and iNOS.

• Biomolecules & Therapeutics
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• v.31 no.6
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• pp.599-610
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• 2023

According to recent evidence, ferroptosis is a major cell death mechanism in the pathogenesis of kidney injury and fibrosis. Despite the renoprotective effects of classical ferroptosis inhibitors, therapeutic approaches targeting kidney ferroptosis remain limited. In this study, we assessed the renoprotective effects of melatonin and zileuton as a novel therapeutic strategy against ferroptosis-mediated kidney injury and fibrosis. First, we identified RSL3-induced ferroptosis in renal tubular epithelial HK-2 and HKC-8 cells. Lipid peroxidation and cell death induced by RSL3 were synergistically mitigated by the combination of melatonin and zileuton. Combination treatment significantly downregulated the expression of ferroptosis-associated proteins, 4-HNE and HO-1, and upregulated the expression of GPX4. The expression levels of p-AKT and p-mTOR also increased, in addition to that of NRF2 in renal tubular epithelial cells. When melatonin (20 mg/kg) and zileuton (20 mg/kg) were administered to a unilateral ureteral obstruction (UUO) mouse model, the combination significantly reduced tubular injury and fibrosis by decreasing the expression of profibrotic markers, such as α-SMA and fibronectin. More importantly, the combination ameliorated the increase in 4-HNE levels and decreased GPX4 expression in UUO mice. Overall, the combination of melatonin and zileuton was found to effectively ameliorate ferroptosis-related kidney injury by upregulating the AKT/mTOR/ NRF2 signaling pathway, suggesting a promising therapeutic strategy for protection against ferroptosis-mediated kidney injury and fibrosis.