scholarly journals Effects of Increased Uric Acid Intake on the Abundance of Urate-anion exchanger and Organic Anion Transporter Proteins in the Rat Kidney

2007 ◽  
Vol 5 (2) ◽  
pp. 62 ◽  
Author(s):  
Sua Kim ◽  
Chang Hwa Lee ◽  
Chong Myung Kang ◽  
Gheun-Ho Kim
2003 ◽  
Vol 49 (3) ◽  
pp. 233-238 ◽  
Author(s):  
Masanori Katakura ◽  
Naomi Kudo ◽  
Mari Okazaki ◽  
Yasuhide Hibino ◽  
Yoichi Kawashima

2008 ◽  
Vol 295 (3) ◽  
pp. C761-C767 ◽  
Author(s):  
William Silverman ◽  
Silviu Locovei ◽  
Gerhard Dahl

Probenecid is a well-established drug for the treatment of gout and is thought to act on an organic anion transporter, thereby affecting uric acid excretion in the kidney by blocking urate reuptake. Probenecid also has been shown to affect ATP release, leading to the suggestion that ATP release involves an organic anion transporter. Other pharmacological evidence and the observation of dye uptake, however, suggest that the nonvesicular release of ATP is mediated by large membrane channels, with pannexin 1 being a prominent candidate. In the present study we show that probenecid inhibited currents mediated by pannexin 1 channels in the same concentration range as observed for inhibition of transport processes. Probenecid did not affect channels formed by connexins. Thus probenecid allows for discrimination between channels formed by connexins and pannexins.


1996 ◽  
Vol 71 ◽  
pp. 291
Author(s):  
Takashi Sekine ◽  
Makoto Hosoyamada ◽  
Yoshikatsu Kanai ◽  
Hitoshi Endou

2007 ◽  
Vol 292 (1) ◽  
pp. F361-F372 ◽  
Author(s):  
Marija Ljubojević ◽  
Daniela Balen ◽  
Davorka Breljak ◽  
Marija Kušan ◽  
Naohiko Anzai ◽  
...  

The renal reabsorption and/or excretion of various organic anions is mediated by specific organic anion transporters (OATs). OAT2 (Slc22a7) has been identified in rat kidney, where its mRNA expression exhibits gender differences [females (F) > males (M)]. The exact localization of OAT2 protein in the mammalian kidney has not been reported. Here we studied the expression of OAT2 mRNA by RT-PCR and its protein by Western blotting (WB) and immunocytochemistry (IC) in kidneys of adult intact and gonadectomized M and F, sex hormone-treated castrated M, and prepubertal M and F rats, and the protein in adult M and F mice. In adult rats, the expression of OAT2 mRNA was predominant in the outer stripe (OS) tissue, exhibiting 1) gender dependency (F > M), 2) upregulation by castration and downregulation by ovariectomy, and 3) strong downregulation by testosterone and weak upregulation by estradiol and progesterone treatment. A polyclonal antibody against rat OAT2 on WB of isolated renal membranes labeled a ∼66-kDa protein band that was stronger in F. By IC, the antibody exclusively stained brush border (BB) of the proximal tubule S3 segment (S3) in the OS and medullary rays (F > M). In variously treated rats, the pattern of 66-kDa band density in the OS membranes and the staining intensity of BB in S3 matched the mRNA expression. The expression of OAT2 protein in prepubertal rats was low and gender independent. In mice, the expression pattern largely resembled that in rats. Therefore, OAT2 in rat (and mouse) kidney is localized to the BB of S3, exhibiting gender differences (F > M) that appear in puberty and are caused by strong androgen inhibition and weak estrogen and progesterone stimulation.


2015 ◽  
Vol 37 (4) ◽  
pp. 1491-1502 ◽  
Author(s):  
Yongping Guo ◽  
Qian Jiang ◽  
Dingkun Gui ◽  
Niansong Wang

Background/Aims: Hyperuricemia is an independent risk factor for chronic kidney disease and cardiovascular disease. Here, we examined the combined protective effects of Chinese herbal formula Si-Wu-Tang and Er-Miao-San on hyperuricemia and renal impairment in rats. Methods: Rats were randomly divided into normal rats, hyperuricemic rats, and hyperuricemic rats orally administrated with benzbromarone (4.5 mg·kg-1·d-1), Si-Wu-Tang (3.78 g·kg-1·d-1) and Si-Wu-Tang plus Er-Miao-San (6.48 g·kg-1·d-1) for 4 weeks. Hyperuricemic rats were orally gavaged with adenine (0.1 g·kg-1·d-1) and potassium oxonate (1.5 g·kg-1·d-1) daily for 4 weeks. Serum uric acid, creatinine, total cholesterol (TCH), triglyceride and blood urea nitrogen (BUN) concentrations, as well as urinary uric acid and microalbuminuria were measured weekly. Serum xanthine oxidase (XOD) activity and renal histopathology were also evaluated. The renal expression of organic anion transporter 1 (OAT1) and organic anion transporter 3 (OAT3) was detected by western blot. Results: Si-Wu-Tang plus Er-Miao-San lowered serum uric acid, creatinine, triglyceride and BUN levels to a greater degree than did Si-Wu-Tang alone. Si-Wu-Tang plus Er-Miao-San ameliorated microalbuminuria and renal histopathology, as well as decreased serum TCH concentration and XOD activity in hyperuricemic rats. Combination of Si-Wu-Tang and Er-Miao-San also led to a greater increase in OAT1 and OAT3 expression than did Siwutang alone. Conclusion: Si-Wu-Tang and Er-Miao-San synergistically ameliorated hyperuricemia and renal impairment in rats through upregulation of OAT1 and OAT3.


2021 ◽  
Author(s):  
Ji-Xiao Zhu ◽  
Hai-Yan Yang ◽  
Wei-Qiong Hu ◽  
Jie Cheng ◽  
Yang Liu ◽  
...  

Abstract Lagotis brachystachya Maxim is an herb widely used in traditional Tibet medicine. Our previous study indicated that total extracts from Lagotis brachystachya could lower uric acid levels. This study aimed to further elucidate the active components (luteolin, luteoloside and apigenin) isolated from Lagotis brachystachya and the underlying mechanism in vitro and vivo. The results showed that treatment with luteolin and luteoloside reversed the reduction of organic anion transporter 1 (OAT1) levels, while apigenin attenuated the elevation of urate transporter 1 (URAT1) and glucose transporter 9 (GLUT9) levels in uric acid-treated HK-2 cells, which were consistent with the finding in the kidney of potassium oxonate (PO)-induced mice. On the other hand, hepatic xanthine oxidase activity was inhibited by the components. In addition, all of these active components improved the morphology of the kidney in hyperuricemic mice. Moreover, molecular docking showed that luteolin, luteoloside and apigenin could bind TLR4 and NLRP3. Consistently, western blot showed that the components inhibited TLR4/MyD88/NLRP3 signaling. In conclusion, these results indicated that luteolin, luteoloside and apigenin could attenuate hyperuricemia by decreasing the production and increasing the excretion of uric acid, which were mediated by the inhibition of inflammatory signaling pathways.


Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1668
Author(s):  
Ok-Kyung Kim ◽  
Jeong-Moon Yun ◽  
Minhee Lee ◽  
Dakyung Kim ◽  
Jeongmin Lee

Hyperuricemia, abnormally excess accumulation of uric acid, is caused by an imbalance between the production and excretion of uric acid and is a major cause of gout. We compared the effects of extracts from Chrysanthemum indicum L. (Ci) and Cornus officinalis Siebold and Zucc. (Co) on hyperuricemia, both individually and in combination (FSU-CC), using hypoxanthine-treated human liver cancer (HepG2) cells, primary mouse renal proximal tubule cells, and potassium oxonate induced hyperuricemic mice. The Ci contained 7.62 mg/g luteolin and 0 mg/g loganin, Co contained 0 mg/g luteolin and 4.90 mg/g loganin, and FSH-CC contained 3.95 mg/g luteolin and 2.48 mg/g loganin. We found that treatment with Ci, Co, and FSU-CC suppressed the activity of xanthine oxidase and mRNA expression of xanthine dehydrogenase while inducing an increase in the expression levels of the organic anion transporter 1 (OAT1) and organic anion transporter 3 (OAT3) proteins and a decrease in the expression levels of glucose transporter 9 (GLUT9) and urate transporter 1 (URAT1) proteins. Particularly, treatment and supplementation with FSU-CC showed stronger effects than those of supplementation with either Ci or Co alone. We observed that the excretion of creatinine and uric acid in the combination of Ci and Co was higher than that observed in their individual supplementations and was similar to that of the normal group. Therefore, our data suggest that a combination of Ci and Co may potentially be used for the development of effective natural anti-hyperuricemic functional foods.


2021 ◽  
Vol 12 ◽  
Author(s):  
Chongxiang Xiong ◽  
Jin Deng ◽  
Xin Wang ◽  
Xiaofei Shao ◽  
Qin Zhou ◽  
...  

Hyperuricemia is an independent risk factor for renal damage and promotes the progression of chronic kidney disease. In this study, we investigated the effect of I-BET151, a small-molecule inhibitor targeting the bromodomain and extraterminal (BET) proteins, on the development of hyperuricemic nephropathy (HN), and the mechanisms involved. Expression levels of bromodomain-containing protein 2 and 4, but not 3 were increased in the kidney of rats with HN; administration of I-BET151 effectively prevented renal dysfunction, decreased urine microalbumin, and attenuated renal fibrosis as indicated by reduced activation of renal interstitial fibroblasts and expression of fibronectin and collagen I in HN rats. Mechanistic studies show that I-BET151 treatment inhibited transition of renal epithelial cells to a mesenchymal cell type as evidenced by preservation of E-cadherin and reduction of vimentin expression. This was coincident with reduced expression of TGF-β1 and dephosphorylation of Smad3 and ERK1/2. I-BET151 was also effective in inhibiting phosphorylation of NF-κB, expression of multiple cytokines and chemokines, and infiltration of macrophages to the injured kidney. Although there were increased serum levels of uric acid and xanthine oxidase, an enzyme that catalyzes production of uric acid, and decreased expression of renal organic anion transporter 1 and 3 that promote urate excretion in the model of HN, and reduced expression levels of urine uric acid, I-BET151 treatment did not affect these responses. Collectively, our results indicate that I-BET151 alleviates HN by inhibiting epithelial to mesenchymal transition and inflammation in association with blockade of TGF-β, ERK1/2 and NF-κB signaling.


2021 ◽  
Author(s):  
Ok-kyung Kim ◽  
Jeong Moon Yun ◽  
Minhee Lee ◽  
Dakyung Kim ◽  
Jeongmin Lee

Abstract Background: Hyperuricemia, abnormally excess accumulation of uric acid, is caused by an imbalance between the production and excretion of uric acid and is a major cause of gout. We compared the effects of extracts from Chrysanthemum indicum L. (Ci) and Cornus officinalis Siebold & Zucc (Co) on hyperuricemia, both individually and in combination (FSU-CC), Methods: We used hypoxanthine-treated human liver cancer (HepG2) cells and primary mouse renal proximal tubule cells for in vitro model, and potassium oxonate-induced hyperuricemic mice for in vivo model.Results: We found that treatment of Ci, Co, and FSU-CC suppressed the activity of xanthine oxidase and mRNA expression of xanthine dehydrogenase, while inducing an increase in the expression levels of the organic anion transporter 1 and organic anion transporter 3 proteins and a decrease in the expression levels of glucose transporter 9 and urate transporter 1 proteins. Particularly, treatment and supplementation with FSU-CC showed stronger effects than those of supplementation with either Ci or Co alone. We observed that the excretion of creatinine and uric acid in the combination of Ci and Co was higher than that observed in their individual supplementations and was similar to that of the normal group.Conclusions: Therefore, our data suggest that a combination of Ci and Co may potentially be used for the development of effective natural anti-hyperuricemic functional foods.


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